Method for producing carbodiimide compound

ABSTRACT

A method for producing a carbodiimide compound, comprising a carbodiimide production step of reacting an aliphatic tertiary isocyanate compound (A) in the presence of an organic alkali metal compound (B) having Lewis basicity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation application of co-pending applicationSer. No. 16/979,484, filed on Sep. 9, 2020, which is the National Phaseunder 35 U.S.C. § 371 of International Application No.PCT/JP2019/009934, filed on Mar. 12, 2019, which claims the benefitunder 35 U.S.C. § 119(a) to Patent Application No. 2018-044526, filed inJapan on Mar. 12, 2018, all of which are hereby expressly incorporatedby reference into the present application.

TECHNICAL FIELD

The present invention relates to a method for producing a carbodiimidecompound, particularly relates to a method for producing a carbodiimidecompound from isocyanate. The present invention also relates to a methodfor producing a polyurethane, use of a carbodiimide compound, acarbodiimide composition, a stabilizer, and an ester-based resincomposition.

BACKGROUND ART

Carbodiimide compounds are useful for various applications, such asstabilizers and hydrolysis inhibitors for various resins such asthermoplastic resins.

It is known to use organic phosphorus catalysts as carbodiimidizationcatalysts in the production of carbodiimide compounds from isocyanates.

For example, PTL 1 describes formation of a polyisocyanate carbodiimideby reacting a polyisocyanate in the presence of a phosphorus-containingcatalyst.

Examples of a carbodiimide formation catalyst in PTL 2 include1-phenyl-2-phospholene-1-oxide, 3-methyl-1-phenyl-2-phospholene-1-oxide,1-phenyl phospholene-1-sulfide, 1-ethyl-2-phospholene-1-oxide,1-ethyl-3-methyl phospholene-1-oxide, and corresponding isomers3-phospholenes.

It is also known to use organic metal compounds as isocyanurationcatalysts in the modification of isocyanates with isocyanurates.

For example, PTL 3 describes use of a carboxylic acid alkali metal saltand a tertiary amine for a catalyst for aiding a trimerization reaction(isocyanuration reaction) of isocyanate. Examples of the carboxylic acidalkali metal salt listed in the PTL include carboxylic acid alkali metalsalts such as sodium acetate, potassium acetate, potassium2-ethylhexoate, potassium adipate, and sodium benzoate. Examples of thetertiary amine listed in the PTL include N-alkylethyleneimine,N-(2-dimethylaminoethyl)-N′-methylpiperazine, andtris-3-dimethylaminopropylhexahydro-s-triazine.

CITATION LIST Patent Literatures

-   PTL 1: JP 51-37996 A-   PTL 2: JP 51-61599 A-   PTL 3: JP 50-159593 A

SUMMARY OF INVENTION Technical Problem

An organic phosphorus compound used as a carbodiimidization catalyst ineach of PTLs 1 and 2 is a very expensive compound.

When the organic phosphorus compound is used to produce a carbodiimidecompound, a problem is that the organic phosphorus compound remaining inthe resulting carbodiimide compound interferes with an object materialto result in difficulty of use. A known method for solving the problem,in which a catalyst is distilled off under reduced pressure during orafter synthesis of a carbodiimide compound, has the problem of causing aprocess to be complicated.

The present invention has been made for solving the above problems, andan object thereof is to provide a method for producing a carbodiimidecompound from an isocyanate compound at a high yield even in the case ofsubstantial no use of any organic phosphorus compound as acarbodiimidization catalyst, as well as a method for producing apolyurethane, use of a carbodiimide compound, a carbodiimidecomposition, a stabilizer, and an ester-based resin composition.

Solution to Problem

The present inventors have made intensive studies, and as a result, havefound that an organic alkali metal compound among organic metalcompounds conventionally utilized as isocyanurate catalysts is useful asa carbodiimidization catalyst to a specified isocyanate and furthermorethe catalyst can be removed by a simple method when, if necessary,removed.

That is, the present invention provides the following [1] to [10].

[1] A method for producing a carbodiimide compound, comprising acarbodiimide production step of reacting an aliphatic tertiaryisocyanate compound (A) in the presence of an organic alkali metalcompound (B) having Lewis basicity.

[2] The method for producing a carbodiimide compound according to [1],wherein the organic alkali metal compound (B) having Lewis basicity isat least one of a metal alkoxide, a metal amide, and a metalcarboxylate.

[3] The method for producing a carbodiimide compound according to [1] or[2], wherein the aliphatic tertiary isocyanate compound (A) is acompound in which at least one aromatic ring is bonded to a tertiarycarbon atom to which an isocyanate group is bonded.

[4] The method for producing a carbodiimide compound according to anyone of [1] to [3], wherein the aliphatic tertiary isocyanate compound(A) is at least one of tetramethylxylylene diisocyanate and3-isopropenyl-α,α-dimethylbenzyl isocyanate.

[5] The method for producing a carbodiimide compound according to anyone of [1] to [4], wherein the aliphatic tertiary isocyanate compound(A) is reacted in the presence of the organic alkali metal compound (B)having Lewis basicity and a phase transfer catalyst (C) in thecarbodiimide production step.

[6] The method for producing a carbodiimide compound according to [5],wherein the phase transfer catalyst (C) is at least one of crown ether,a quaternary ammonium salt, and a compound represented by the followinggeneral formula (1):

wherein X and Y are each independently a methyl group, an ethyl group, apropyl group, a butyl group, or a phenyl group; R¹ is an alkylene grouphaving 2 to 3 carbon atoms; and m is an integer of 2 to 500.

[7] The method for producing a carbodiimide compound according to anyone of [1] to [6], wherein the method comprises an end-capping step ofend-capping a portion of an isocyanate group in the aliphatic tertiaryisocyanate compound (A) with an end-capping agent at at least one timepoint among three time points, before the carbodiimide production step,during the production step, and after the production step, and theend-capping agent is a compound (D-1) represented by the followinggeneral formula (2-1);

wherein Z is a methyl group, an ethyl group, a propyl group, a butylgroup, or a phenyl group; R² is an alkylene group having 2 to 3 carbonatoms; and n is an integer of 2 to 500.

[8] The method for producing a carbodiimide compound according to anyone of [1] to [7], wherein the method comprises a chain extension stepof reacting a portion of an isocyanate group in the aliphatic tertiaryisocyanate compound (A) with a chain extender at at least one time pointamong three time points, before the carbodiimide production step, duringthe production step, and after the production step, and the chainextender is a compound (D-2) represented by the following generalformula (2-2);

wherein R³ is an alkylene group having 2 to 3 carbon atoms; and p is aninteger of 2 to 500.

[9] The method for producing a carbodiimide compound according to anyone of [1] to [8], wherein the method comprises an adsorption andremoval step of performing adsorption and removal of the organic alkalimetal compound (B) having Lewis basicity, with an adsorbent (E), afterthe carbodiimide production step.

[10] The method for producing a carbodiimide compound according to [9],wherein the adsorbent (E) is at least one of a synthetic aluminumsilicate-based adsorbent, synthetic magnesium silicate, an acidiccation-exchange resin, a basic anion-exchange resin, alumina, a silicagel-based adsorbent, a zeolite-based adsorbent, hydrotalcites, amagnesium oxide-aluminum oxide-based solid solution, aluminum hydroxide,magnesium oxide, and an aluminum hydroxide-sodium hydrogen carbonatecoprecipitate (dawsonite).

[11] A method for producing a stabilizer having a purity of 90% by massor more and comprising no phospholene oxides or comprising phospholeneoxides at a content of 1 ppm by mass or less, wherein the methodcomprises the production method according to any one of [1] to [10].

[12] A method for producing a polyurethane, comprising

reacting a polyol and a diisocyanate in the presence of a stabilizer tothereby obtain a polyurethane, preferably a thermoplastic polyurethane,wherein

the stabilizer comprises an aliphatic tertiary carbodiimide derived froman aliphatic tertiary isocyanate compound and comprises an alkali metalat a content of less than 2000 ppm by mass.

The method for producing a polyurethane according to [12], wherein anamount of the aliphatic tertiary carbodiimide derived from an aliphatictertiary isocyanate compound, to be added, based on a total amount of100 parts by mass of the polyol and the diisocyanate is 0.1 to 2 partsby mass, preferably 0.5 to 1 part by mass.

[14] The method for producing a polyurethane according to [12] or [13],wherein the aliphatic tertiary carbodiimide derived from an aliphatictertiary isocyanate compound is preferably metered and loaded at atemperature of 20 to 50° C., particularly preferably 25 to 35° C., inthe form of a liquid in a continuous or batch manner.

[15] A method for producing a polyurethane, comprising

reacting a polyol and a diisocyanate in the presence of a stabilizer tothereby obtain a polyurethane, preferably a thermoplastic polyurethane,wherein

the stabilizer is a carbodiimide compound produced by the method forproducing a carbodiimide compound according to any one of [1] to [10].

[16] Use of a carbodiimide compound according to any one of [1] to [10],for prevention of hydrolysis.

[17] A carbodiimide composition comprising a carbodiimide compound withan aliphatic tertiary isocyanate compound (A) as a structural unit, andan alkali metal, and comprising no phospholene oxides or comprisingphospholene oxides at a content of 1 ppm by mass or less.

[18] The carbodiimide composition according to [17], further comprisinga phase transfer catalyst (C).

[19] A stabilizer comprising a carbodiimide compound with an aliphatictertiary isocyanate compound (A) as a structural unit, and an alkalimetal, and comprising no phospholene oxides or comprising phospholeneoxides at a content of 1 ppm by mass or less.

[20] The stabilizer according to [19], further comprising a phasetransfer catalyst (C).

[21] An ester-based resin composition comprising the carbodiimidecomposition according to [17] or [18], and an ester-based resin.

[22] The ester-based resin composition according to [21], comprising thecarbodiimide composition at a content of 0.2 to 5.0 parts by mass basedon 100 parts by mass of the ester-based resin.

[23] An ester-based resin composition comprising the stabilizeraccording to [19] or [20], and an ester-based resin.

Advantageous Effects of Invention

According to the present invention, it is possible to produce acarbodiimide compound at a high yield by reacting an aliphatic tertiaryisocyanate compound, even in the case of substantial no use of anyorganic phosphorus compound as a carbodiimidization catalyst.

DESCRIPTION OF EMBODIMENTS

Hereinafter, the present invention will be described with reference toembodiments in detail.

1. Method for Producing Carbodiimide Compound

A method for producing a carbodiimide compound according to the presentembodiment comprises a carbodiimide production step of reacting analiphatic tertiary isocyanate compound (A) in the presence of an organicalkali metal compound (B) having Lewis basicity.

As described above, an organic alkali metal compound usually acts as acatalyst that aids an isocyanate trimerization reaction (isocyanurationreaction). When the aliphatic tertiary isocyanate compound (A) isreacted as isocyanate, however, the organic alkali metal compound (B)having Lewis basicity acts as a carbodiimidization catalyst. Thus, adimer (uretdione), a trimer (isocyanurate), and any other multimer areinhibited or prevented from being produced, and a carbodiimide compoundcan be obtained at a high yield.

In the method for producing a carbodiimide compound according to thepresent embodiment, preferably substantially no organic phosphoruscompound is used, more preferably no organic phosphorus compound is use.When no organic phosphorus compound is used, a catalyst removal stepperformed after carbodiimide production can be omitted, provided that aremoval step of any other catalyst may be performed even in no use ofany organic phosphorus compound.

The method for producing a carbodiimide compound according to thepresent embodiment may comprise any step other than the carbodiimideproduction step. For example, the method may comprise an end-cappingstep of end-capping a portion of an isocyanate group derived from thealiphatic tertiary isocyanate compound (A) with a compound having afunctional group reactive with isocyanate and/or a chain extension stepof mutually linking isocyanate, for the purpose of molecular weightcontrol, at at least one time point among three time points, before thecarbodiimide production step, during the production step, and after theproduction step.

For example, when the end-capping step is performed before theproduction step, a portion of an isocyanate group in the aliphatictertiary isocyanate compound (A) is preferably end-capped. When theend-capping step is performed during the production step, a portion of aterminal isocyanate group of a polycarbodiimide produced by acarbodiimidization reaction of the aliphatic tertiary isocyanatecompound (A) and a portion of an isocyanate group in the aliphatictertiary isocyanate compound (A) before such a reaction are preferablyend-capped. When the end-capping step is performed afterpolycarbodiimide production, a terminal isocyanate group of apolycarbodiimide compound produced is preferably fully end-capped.

When the chain extension step is performed before the production step, achain extender is preferably provided to a portion of an isocyanategroup in the aliphatic tertiary isocyanate compound (A). When the chainextension step is performed during the production step, a chain extenderis preferably provided to a portion of a terminal isocyanate group of apolycarbodiimide produced by a carbodiimidization reaction of thealiphatic tertiary isocyanate compound (A) and a portion of anisocyanate group in the aliphatic tertiary isocyanate compound (A)before such a reaction. When the chain extension step is performed afterpolycarbodiimide production, a chain extender is preferably provided toa portion or full of a terminal isocyanate group in a polycarbodiimidecompound produced.

The end-capping step may also be performed only at any time point beforethe carbodiimide production step, during the production step, or afterthe production step. The chain extension step may also be performed onlyat any time point before the carbodiimide production step, during theproduction step, or after the production step.

The method may comprise an adsorption and removal step of performingadsorption and removal of the organic alkali metal compound (B) havingLewis basicity, with an adsorbent (E), after the carbodiimide productionstep.

No organic phosphorus compound is substantially used, preferably used atall, in the method for producing a carbodiimide compound according tothe present embodiment. When no organic phosphorus compound is used, acatalyst removal step performed after carbodiimide production can beomitted, provided that a removal step of any other catalyst may beperformed even in no use of any organic phosphorus compound.

Next, each of the steps will be described.

[Carbodiimide Production Step]

The method for producing a carbodiimide compound according to thepresent embodiment comprises a carbodiimide production step of reactingan aliphatic tertiary isocyanate compound (A) in the presence of anorganic alkali metal compound (B) having Lewis basicity.

<Aliphatic Tertiary Isocyanate Compound (A)>

The aliphatic tertiary isocyanate compound (A) in the present embodimentrefers to an isocyanate compound in which an isocyanate group isdirectly bonded to a carbon atom other than those on an aromatic ringand such a carbon atom to which the isocyanate group is directly bondedis a tertiary carbon atom.

For example, a compound in which an isocyanate group is directly bondedto a tertiary carbon atom of a hydrocarbon forming a chain structure,and a compound in which an isocyanate group is directly bonded to atertiary carbon atom forming an alicyclic structure each correspond tothe aliphatic tertiary isocyanate compound (A). A compound in which,even if an aromatic ring is in its molecule, an isocyanate group isdirectly bonded not to the aromatic ring, but to a tertiary carbon atomother than those on the aromatic ring, also corresponds to the aliphatictertiary isocyanate compound (A).

The aliphatic tertiary isocyanate compound (A) may be any of amonoisocyanate compound, a diisocyanate compound, and an isocyanatecompound in which three or more isocyanate groups are present in onemolecule.

A compound, in which two or more isocyanate groups are present in onemolecule, corresponds to the aliphatic tertiary isocyanate compound (A)as long as at least one isocyanate group is directly bonded to atertiary carbon atom other than those on an aromatic ring. Herein, allsuch isocyanate groups in one molecule are each preferably directlybonded to a tertiary carbon atom other than those on an aromatic ring.

A hydrocarbon moiety except for an isocyanate group in the aliphatictertiary isocyanate compound (A) may or may not have a substituent otherthan a hydrocarbon group, preferably has no substituent other than ahydrocarbon group.

The aliphatic tertiary isocyanate compound (A) may or may not have achain structure, may or may not have an alicyclic structure, and may ormay not have an aromatic ring.

The aliphatic tertiary isocyanate compound (A) is preferably a compoundin which at least one aromatic ring is bonded to a tertiary carbon atomto which an isocyanate group is bonded. Although the reason is notclear, it is considered that, when such an aromatic ring is bonded, anintermediate made by attacking an isocyanate group by the organic alkalimetal (B) having Lewis basicity is stabilized in generation of such anintermediate and thus carbodiimidization easily progresses.

When a plurality of tertiary carbon atoms each bonded to an isocyanategroup are present in one molecule, at least one aromatic ring may bebonded to at least one of such tertiary carbon atoms. When a pluralityof tertiary carbon atoms each bonded to an isocyanate group are presentin one molecule, however, at least one aromatic ring is preferablybonded to each of all such tertiary carbon atoms.

The aliphatic tertiary isocyanate compound (A) is preferably a compoundrepresented by the following general formula (3):

wherein R³ to R⁵ are each independently a monovalent residue of anyorganic compound (provided that a carbon atom in each of R³ to R⁵ isindependently bonded to a carbon atom in the formula (3)), preferably asubstituted or unsubstituted hydrocarbon group, for example, asubstituted or unsubstituted alkyl group, alkenyl group or aromaticgroup, for example, an alkyl group or aromatic group not substitutedwith any group other than an isocyanate group, namely, an alkyl groupsubstituted or unsubstituted with an isocyanate group, or an aromaticgroup substituted or unsubstituted with an isocyanate group.

R³ to R⁵ may each independently have one or more isocyanate groups.Alternatively, one of R³ to R⁵ may have one or more isocyanate groups,or R³ to R⁵ may have no isocyanate group.

R³ to R⁵ are not particularly limited, and may each independently have,for example, 1 to 20 carbon atoms, for example, 1 to 10 carbon atoms, ormore carbon atoms.

At least one of R³ to R⁵ is preferably a substituted or unsubstitutedaromatic group. Although the reason is not clear, it is considered that,when such a substituted or unsubstituted aromatic group is adopted, anintermediate made by attacking an isocyanate group by the organic alkalimetal (B) having Lewis basicity is stabilized in generation of such anintermediate and thus carbodiimidization easily progresses.

The substituted or unsubstituted aromatic group is preferably asubstituted or unsubstituted aryl group having 6 to 20 carbon atoms,more preferably a substituted or unsubstituted phenyl group. Thesubstituent in the substituted or unsubstituted aromatic group ispreferably an alkyl group having 1 to 20 carbon atoms or an alkenylgroup having 2 to 20 carbon atoms, more preferably an alkyl group having1 to 4 carbon atoms or an alkenyl group having 2 to 4 carbon atoms.

Examples of the compound represented by the general formula (3) includemonoisocyanates such as 3-isopropenyl-α,α-dimethylbenzyl isocyanate(TMI); and diisocyanates such as tetramethylxylylene diisocyanate(TMXDI).

When the aliphatic tertiary isocyanate compound (A) is a compound inwhich an isocyanate group is directly bonded to a tertiary carbon atomof a hydrocarbon forming an alicyclic structure, examples of thealicyclic structure include an adamantane structure, a norbornanestructure, a norbornadiene structure, a bicycloundecane structure, adecahydronaphthalene structure, a cubane structure, a basketanestructure, and a housane structure. A substituent other than anisocyanate group may or may not be bonded to the alicyclic structure.

The aliphatic tertiary isocyanate compound (A) is preferably at leastone of tetramethylxylylene diisocyanate (TMXDI) and3-isopropenyl-α,α-dimethylbenzyl isocyanate (TMI), more preferably TMXDIor TMI, further preferably TMXDI.

When the aliphatic tertiary isocyanate compound (A) is a monoisocyanatecompound, the method for producing a carbodiimide compound according tothe present embodiment enables a decarboxylation condensation reactionof isocyanate groups of two such monoisocyanate compounds to occur,thereby producing a monocarbodiimide compound.

When the aliphatic tertiary isocyanate compound (A) is a polyisocyanatecompound, the method for producing a carbodiimide compound according tothe present embodiment not only enables two such polyisocyanatecompounds to be polymerized, thereby producing a monocarbodiimidecompound, but also enables three or more such polyisocyanate compoundsto be polymerized, thereby producing a polycarbodiimide compound.

The monoisocyanate compound means a compound having one isocyanategroup. The polyisocyanate compound means a compound having two or moreisocyanate groups. The term “isocyanate compound” conceptuallyencompasses the monoisocyanate compound and the polyisocyanate compound.

The monocarbodiimide compound means a compound having one carbodiimidegroup. The polycarbodiimide compound means a compound having two or morecarbodiimide groups. The term “carbodiimide compound” conceptuallyencompasses the monocarbodiimide compound and the polycarbodiimidecompound.

A polymerization degree of the carbodiimide compound, of P, in thepresent embodiment means that, when a carbodiimide compound is producedby subjecting such an isocyanate compound to a decarboxylationcondensation reaction, the number of carbodiimide group(s) generated inone molecule of the carbodiimide compound is P. For example, when P+1diisocyanate compounds are polymerized to produce a polycarbodiimidecompound having P carbodiimide group(s), the polymerization degree ofthe resulting carbodiimide compound is P. Even when P−1 diisocyanatecompound(s) and two such monoisocyanate compounds are polymerized toproduce an end-capped polycarbodiimide compound having P carbodiimidegroup(s), the polymerization degree of the resulting carbodiimidecompound is P.

The NCO % in a carbodiimide compound generated by a carbodiimidizationreaction of the aliphatic tertiary isocyanate compound (A) in thepresent embodiment means the content (% by mass) of an isocyanate group(NCO group) in the resulting carbodiimide compound. The NCO % can bedetermined by a method described in Examples.

<Organic Alkali Metal Compound (B) Having Lewis Basicity>

The carbodiimidization catalyst for use in the present embodiment is anorganic alkali metal compound (B) having Lewis basicity. The organicalkali metal compound (B) having Lewis basicity for use in the presentembodiment contains no phosphorus atom in its molecule. Thus, there areavoided the problems of the remaining organic phosphorus compound in theresulting carbodiimide compound, which interferes with an objectmaterial to result in difficulty of use in use of the resultant as anadditive, and of the occurrence of any labor hour for removal of theremaining organic phosphorus compound.

The amount of the organic alkali metal compound (B) having Lewisbasicity, to be added, based on 100 parts by mass of the aliphatictertiary isocyanate compound (A) may be 0.01 parts by mass or more andis preferably 0.01 parts by mass or more and 5 parts by mass or less,although the upper limit thereof is not particularly set. An amount of0.01 parts by mass or more allows the promotion effect of a carbodiimidereaction to be excellent, and an amount of more than 5 parts by massdoes not allow the promotion effect of a carbodiimide reaction to besufficiently enhanced even by further addition. The amount to be addedis more preferably 0.05 to 3 parts by mass and further preferably 0.1 to1 part by mass from such a viewpoint.

The organic alkali metal compound (B) having Lewis basicity ispreferably at least one of a metal alkoxide, a metal amide, and a metalcarboxylate, and, in one aspect, is a metal amide.

<<Metal Alkoxide>>

The metal alkoxide is an alkali metal alkoxide.

The alkali metal alkoxide is preferably a compound represented by thefollowing general formula (5):

M-OR¹⁰  (5)

wherein M is an alkali metal, preferably at least one of lithium (Li),sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium(Fr), more preferably at least one of lithium (Li), sodium (Na), cesium(Cs), and potassium (K), and further preferably at least one lithium(Li), sodium (Na), and potassium (K); and

wherein R¹⁰ is preferably an alkyl group having 1 to 20 carbon atoms oran aryl group having 6 to 20 carbon atoms, more preferably an alkylgroup having 1 to 20 carbon atoms, further preferably an alkyl grouphaving 1 to 10 carbon atoms, still further preferably an alkyl grouphaving 1 to 6 carbon atoms, still further preferably an alkyl grouphaving 1 to 4 carbon atoms, still further preferably an alkyl grouphaving 2 to 4 carbon atoms, and still further preferably at least one ofan ethyl group and a tert-butyl group.

The alkali metal alkoxide is preferably at least one of potassiumtert-butoxide, sodium tert-butoxide, potassium ethoxide, and sodiumethoxide, and more preferably at least one of potassium tert-butoxideand sodium ethoxide.

<<Metal Amide>>

The metal amide is preferably an alkali metal amide such as lithiumamide, sodium amide, potassium amide, or cesium amide, more preferablylithium amide, and further preferably lithium diisopropyl amide (LDA).

<<Metal Carboxylate>>

The metal carboxylate is preferably an alkali metal acetate, morepreferably at least one of potassium acetate and cesium acetate.

A suitable type of an organic compound bonded to an alkali metal in theorganic alkali metal compound (B) having Lewis basicity is differentdepending on the type of the alkali metal.

That is, when the alkali metal is lithium, sodium, or potassium, theorganic alkali metal compound (B) having Lewis basicity is preferably atleast one of a metal alkoxide, a metal amide, and a metal carboxylate,and more preferably at least one of a metal alkoxide and a metal amide,from the viewpoints of handleability and stability.

When the alkali metal is cesium, the organic alkali metal compound (B)having Lewis basicity is preferably at least one of cesium alkoxide,cesium amide, and cesium carboxylate, and more preferably cesiumcarboxylate, from the viewpoints of handleability and stability.

<Phase Transfer Catalyst (C)>

The aliphatic tertiary isocyanate compound (A) may be reacted in thepresence of the organic alkali metal compound (B) having Lewis basicityand a phase transfer catalyst (C) in the carbodiimide production step.Thus, the carbodiimide compound can be more rapidly obtained.

The “phase transfer catalyst” in the present embodiment refers to areagent for use in a reaction of an organic compound insoluble in waterand a compound insoluble in an organic solvent, particularly refers to areagent for use in an efficient reaction of such a tertiary isocyanategroup-containing compound (A) and the organic alkali metal compound (B)having Lewis basicity.

The amount of the phase transfer catalyst (C) to be added may be 0.01parts by mass or more based on 100 parts by mass of the aliphatictertiary isocyanate compound (A), and the upper limit thereof is notparticularly set. An amount of 0.01 parts by mass or more allows thepromotion effect of a carbodiimide reaction to be excellent, and anamount of 300 parts by mass or more does not allow the promotion effectof a carbodiimide reaction to be sufficiently enhanced even by furtheraddition. The amount to be added is more preferably 0.01 to 300, furtherpreferably 0.05 to 200 parts by mass, and still further preferably 0.1to 100 parts by mass, from such a viewpoint. When the amount of thephase transfer catalyst (C) to be added is decreased, the effect can beexerted even in the case of an amount of 10 parts by mass or less, forexample, 5 parts by mass or less.

The phase transfer catalyst (C) for use in the present embodiment is notparticularly limited, and is preferably at least one of crown ether, aquaternary ammonium salt, and polyalkylene glycol dialkyl ether, morepreferably at least one crown ether, a quaternary ammonium salt, and acompound represented by general formula (1), described below.

Among these, crown ether is more preferable from the viewpoint of anenhancement in reaction rate, and at least one of a quaternary ammoniumsalt and a polyalkylene glycol dialkyl ether is more preferable from theviewpoint of economic efficiency.

<<Crown Ether>>

The crown ether is not particularly limited, and may be any narrowlydefined crown ether represented by general structure formula(—CH₂—CH₂—O—)_(n) (n is an integer), may be any thiacrown ether in whichsome or all oxygen atoms forming a crown ether ring are each substitutedwith a sulfur atom, or may be any azacrown ether in which some or allthe oxygen atoms are each substituted with NR (R is a substituent) orthe like. Such crown ether may be modified. For example, any narrowlydefined crown ether not modified may also be used.

The crown ether is preferably at least one of 4′-acetylbenzo-15-crown5-ether, 4′-acetylbenzo-18-crown 6-ether, 4′-aminobenzo-15-crown5-ether, 1-aza-12-crown 4-ether, 1-aza-15-crown 5-ether, 1-aza-18-crown6-ether, benzo-12-crown 4-ether, benzo-15-crown 5-ether, benzo-18-crown6-ether, bis(1,4-phenylene)-34-crown 10-ether, 4′-bromobenzo-15-crown5-ether, 4′-bromobenzo-18-crown 6-ether, 4′-carboxybenzo-15-crown5-ether, 4′-carboxybenzo-18-crown 6-ether, 15-crown4[4-(2,4-dinitrophenylazo)phenol], 18-crown5[4-(2,4-dinitrophenylazo)phenol], 12-crown 4-ether, 15-crown 5-ether,18-crown 6-ether, 24-crown 8-ether, 4,10-diaza-12-crown 4-ether,4,10-diaza-15-crown 5-ether, 4,13-diaza-18-crown 6-ether,dibenzo-15-crown 5-ether, dibenzo-18-crown 6-ether, dibenzo-21-crown7-ether, dibenzo-24-crown 8-ether, dibenzo-30-crown 10-ether,N,N′-dibenzyl-4,13-diaza-18-crown 6-ether, dicyclohexano-18-crown6-ether, 4′-formylbenzo-15-crown 5-ether, 4′-formylbenzo-18-crown6-ether, 1,4,7,10,13,16-hexaazacyclooctadecane,1,4,7,10,13,16-hexaazacyclooctadecanehexahydrochloride,4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane,2-(hydroxymethyl)-12-crown 4-ether, 2-(hydroxymethyl)-15-crown 5-ether,2-(hydroxymethyl)-18-crown 6-ether, 4′-methoxycarbonylbenzo-15-crown5-ether, 4′-nitrobenzo-15-crown 5-ether, 4′-nitrobenzo-18-crown 6-ether,N-phenylaza-15-crown 5-ether, 1,4,7,10-tetraazacyclododecane,1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid,1,4,7,10-tetraazacyclododecane tetrahydrochloride,1,4,8,12-tetraazacyclopentadecane, 1,4,8,11-tetraazacyclotetradecane,1,4,7,10-tetrabenzyl-1,4,7,10-tetraazacyclododecane,tetraethyl-1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetate,1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane,1,4,8,11-tetrathiacyclotetradecane, 1,5,9-triazacyclododecane,1,4,7-triazacyclononane, 1,4,7-triazacyclononane trihydrochloride,tri-tert-butyl-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate,tri-tert-butyl-1,4,7,10-tetraazacyclododecane-1,4,7-triacetate,1,4,7-trimethyl-1,4,7-triazacyclononane (stabilized with NaHCO₃), and1,4,7-trithiacyclononane.

Among these, at least one of 12-crown 4-ether, 15-crown 5-ether,18-crown 6-ether, and 24-crown 8-ether is more preferable, and 18-crown6-ether and/or 15-crown 5-ether are/is further preferable.

The crown ether is preferably appropriately selected depending on thetype of the cation in the organic alkali metal compound (B) having Lewisbasicity. For example, 18-crown 6-ether is preferable when the cation ispotassium (K), and 15-crown 5-ether is preferable when the cation issodium (Na).

<<Quaternary Ammonium Salt>>

The quaternary ammonium salt is not particularly limited, and ispreferably at least one of tetrabutylammonium bromide,tetrabutylammonium iodide, tetrabutylammonium-2-ethylhexanoate,tetrabutylammonium hydrogen sulphate, tetrabutylammonium chloride,tetrabutylammonium fluoride trihydrate, tetrabutylaminium nitrate(Tetrabutylammonium nitrate), tetrabutylaminium nitrite(Tetrabutylammonium nitrite), tetrabutylammonium acetate,tetrabutylammonium triiodide, tetraethylammonium bromide,tetraethylammonium chloride, tetraethylammonium fluoride dihydrate,tetrapropylammonium bromide, tetrapropylammonium chloride,tetramethylammonium chloride, benzyltriethylammonium chloride,benzyltriethylammonium bromide, benzyltrimethylammonium chloride,benzyltrimethylammonium bromide, benzyltrimethylammonium dichloroiodate,benzyltributylammonium chloride, benzyltributylammonium bromide,methyltributylammonium chloride, methyltributylammonium bromide,methyltriethylammonium chloride, methyltriethylammonium bromide,phenyltrimethylammonium chloride, behentrimonium chloride,cetyltrimethylammonium bromide, cetyltrimethylammonium chloride,cetyltrimethylammonium hydrogen sulphate, cetalkonium chloride,cetalkonium bromide, cetyldimethylbenzylammonium chloride,cetyldimethylethylammonium bromide, cetrimide, didecyldimethylammoniumchloride, dodecyltrimethylammonium chloride, dodecyltrimethylammoniumbromide, myristyltrimethylammonium bromide, methyltrioctylammoniumchloride, tetra-n-octylammonium bromide, trimethyl-n-octylammoniumbromide, and trioctyl methyl ammonium bromide.

Among these, a tetrabutylammonium salt, for example,tetrabutylammonium-2-ethylhexanoate is preferable from the viewpoint ofavailability.

<<Polyalkylene Glycol Dialkyl Ether>>

The polyalkylene glycol dialkyl ether is not particularly limited, andis preferably a compound represented by the following general formula(1);

wherein X and Y are each independently a methyl group, an ethyl group, apropyl group, a butyl group, or a phenyl group; R¹ is an alkylene grouphaving 2 to 3 carbon atoms; and m is an integer of 2 to 500, preferablyan integer of 3 to 300, and more preferably an integer of 4 to 200.

The compound represented by the formula (1) is preferably at least oneof polyoxyethylene dialkyl ether and polyoxypropylene dialkyl ether.

The polyoxyethylene dialkyl ether is preferably at least one ofpolyoxyethylene dimethyl ether, polyoxyethylene diethyl ether,polyoxyethylene dipropyl ether, polyoxyethylene dibutyl ether, andpolyoxyethylene diphenyl ether.

The polyoxypropylene dialkyl ether is preferably at least one ofpolyoxypropylene dimethyl ether, polyoxypropylene diethyl ether,polyoxypropylene dipropyl ether, polyoxypropylene dibutyl ether, andpolyoxypropylene diphenyl ether.

The number average molecular weight of the polyalkylene glycol dialkylether is preferably 100 or more from the viewpoint of an enhancement inreaction rate of a carbodiimidization reaction of the tertiaryisocyanate group-containing compound (A), and is preferably 5000 or lessfrom the viewpoints of handleability and solubility. The number averagemolecular weight is more preferably 100 to 1000, further preferably 100to 800, still further preferably 200 to 700, still further preferably250 to 700, and still further preferably 300 to 600 from the sameviewpoints.

<Other Component>

Any component other than the above may be added in the carbodiimideproduction step.

For example, an organic solvent may be added. The organic solvent ispreferably an organic solvent having no active hydrogen group and havinga higher boiling point than the temperature in synthesis, for example,ethylene glycol monomethyl ether acetate (118.13), diethylene glycoldimethyl ether (134.18), dipropylene glycol dimethyl ether (162.23),diethylene glycol ethyl methyl ether (148.20), diethylene glycolisopropyl methyl ether (162.23), diethylene glycol diethyl ether(162.23), diethylene glycol butyl methyl ether (176.26), tripropyleneglycol dimethyl ether (206.28), triethylene glycol dimethyl ether(178.23), diethylene glycol dibutyl ether (218.34), triethylene glycolbutyl methyl ether (220.31), or tetraethylene glycol dimethyl ether(222.28). Thus, the reaction rate of the carbodiimidization reaction maybe enhanced and/or the resulting polycarbodiimide is easily adjusted interms of the viscosity thereof. Each number in parentheses representseach molecular weight.

The amount of such other component to be added is preferably 200 partsby mass or less, more preferably 100 parts by mass or less, and furtherpreferably 10 parts by mass or less based on 100 parts by mass of thetertiary isocyanate group-containing compound (A).

<Reaction Conditions>

The reaction temperature in the carbodiimide production step isappropriately set depending on the type of the aliphatic tertiaryisocyanate compound (A).

The reaction temperature is preferably 50° C. or more, more preferably80° C. or more, and further preferably 100° C. or more, and, when thedecomposition temperature of the aliphatic tertiary isocyanate compound(A) is X° C., the reaction temperature is preferably X° C. or less, morepreferably X−5° C. or less, and further preferably X−10° C. or less.

For example, when the aliphatic tertiary isocyanate compound (A) is atleast one of tetramethylxylylene diisocyanate and3-isopropenyl-α,α-dimethylbenzyl isocyanate, the reaction temperature ispreferably 80 to 200° C., more preferably 100 to 190° C., and furtherpreferably 130 to 180° C.

The reaction atmosphere is preferably an atmosphere of an inert gas suchas a nitrogen gas. The method for inclusion of the inert gas may be in aflowing manner or in a bubbling manner for inclusion into a liquid.

[End-Capping Step]

The method for producing carbodiimide in the present embodiment maycomprise an end-capping step of reacting a portion of an isocyanategroup in the aliphatic tertiary isocyanate compound (A) with anend-capping agent, at at least one time point among three time points,before the carbodiimide production step, during the production step, andafter the production step.

The end-capping step enables the polymerization degree of the resultingcarbodiimide compound to be controlled.

The end-capping agent may be any organic compound having a functionalgroup reactive with a terminal isocyanate group of the carbodiimidecompound. Examples of the organic compound having a functional groupreactive with such an isocyanate group include a compound having activehydrogen, such as alcohol, amine, and carboxylic acid, a compound havinga monoisocyanate group, and a compound (D-1) represented by generalformula (2-1), described below, and a compound (D-1) represented bygeneral formula (2-1), described below, is preferable.

The end-capping step may be performed at at least one time point amongthree time points, before the carbodiimide production step, during theproduction step, and after the production step, may be performed at onlyany one time point, or may be performed, for example, before theproduction step.

The aliphatic tertiary isocyanate compound (A) is partially end-cappedwith the end-capping agent in the end-capping step. Such an aliphatictertiary isocyanate compound (A) partially end-capped can be thussubjected to the carbodiimide production step, thereby producing acarbodiimide compound which is end-capped. Furthermore, thepolymerization degree of the resulting carbodiimide compound can becontrolled. It is noted that the aliphatic tertiary isocyanate compound(A) here used may be an aliphatic tertiary isocyanate compound (A) inwhich an isocyanate group is partially end-capped in advance, and theend-capping step may be omitted.

<Compound (D-1) Represented by General Formula (2-1)>

The compound (D-1) for use in the present embodiment is represented bythe following general formula (2-1);

wherein Z is a methyl group, an ethyl group, a propyl group, a butylgroup, or a phenyl group; R² is an alkylene group having 2 to 3 carbonatoms; and n is an integer of 2 to 500, preferably an integer of 3 to300, and more preferably an integer of 4 to 200.

The compound (D-1) represented by the formula (2-1) is preferably atleast one of polyoxyethylene monoalkyl ether and polyoxypropylenemonoalkyl ether.

The polyoxyethylene monoalkyl ether is preferably at least one ofpolyoxyethylene monomethyl ether, polyoxyethylene monoethyl ether,polyoxyethylene monopropyl ether, polyoxyethylene monobutyl ether, andpolyoxyethylene monophenyl ether.

The polyoxypropylene monoalkyl ether is preferably at least one ofpolyoxypropylene monomethyl ether, polyoxypropylene monoethyl ether,polyoxypropylene monopropyl ether, polyoxypropylene monobutyl ether, andpolyoxypropylene monophenyl ether.

The compound (D-1) is used as the end-capping agent, thereby partiallyend-capping the aliphatic tertiary isocyanate compound (A) due to aurethanization reaction of a portion of an isocyanate group in thealiphatic tertiary isocyanate compound (A) with a hydroxyl group of thecompound (D-1). Thus, the aliphatic tertiary isocyanate compound (A) ispartially end-capped with the compound (D-1) and then subjected to thecarbodiimide production step, and thus is enhanced in reaction rate ofthe carbodiimidization reaction because a residue of the compound (D-1)acts in the same manner as in the phase transfer catalyst.

Such end-capping of the aliphatic tertiary isocyanate compound (A) withthe compound (D-1) can be performed at at least one time point amongthree time points, before the above-mentioned carbodiimide productionstep, during the production step, and after the production step, and ispreferably performed before the production step.

The number average molecular weight of the compound (D-1) is preferably100 or more from the viewpoint of an enhancement in reaction rate of thecarbodiimidization reaction of the tertiary isocyanate group-containingcompound (A), and is preferably 5000 or less from the viewpoints ofhandleability and solubility. The number average molecular weight ismore preferably 100 to 1000, further preferably 100 to 800, stillfurther preferably 200 to 700, still further preferably 250 to 700, andstill further preferably 300 to 600 from the same viewpoints.

The amount of the compound (D-1) to be added can be appropriatelyselected depending on the polymerization degree of a carbodiimidecompound to be produced.

The amount of the compound (D-1) to be added is here preferably 0.01parts by mass or more, more preferably 0.1 parts by mass or more, andfurther preferably 1.0 parts by mass or more based on 100 parts by massof the aliphatic tertiary isocyanate compound (A), from the viewpoint ofpromotion of the carbodiimide reaction. The amount of the compound (D-1)to be added is preferably 200 parts by mass or less, more preferably 50parts by mass or less, and further preferably 5.0 parts by mass or lessbased on 100 parts by mass of the aliphatic tertiary isocyanate compound(A) from an economic viewpoint and from the viewpoint of securement ofthe concentration of carbodiimide.

<Reaction Conditions>

The reaction temperature in the end-capping step is appropriately setdepending on the type of the aliphatic tertiary isocyanate compound (A).

The reaction temperature is preferably 50° C. or more, more preferably80° C. or more, further preferably 100° C. or more, and, when thedecomposition temperature of the aliphatic tertiary isocyanate compound(A) is X° C., the reaction temperature is preferably X° C. or less, morepreferably X−5° C. or less, and further preferably X−10° C. or less.

A urethanization catalyst may be, if necessary, used to allow thereaction to occur at a lower temperature.

For example, when the aliphatic tertiary isocyanate compound (A) is atleast one of tetramethylxylylene diisocyanate and3-isopropenyl-α,α-dimethylbenzyl isocyanate, the reaction temperature ispreferably 80 to 200° C., more preferably 100 to 190° C., and furtherpreferably 130 to 180° C.

The reaction atmosphere is preferably an atmosphere of an inert gas suchas a nitrogen gas. The method for inclusion of the inert gas may be in aflowing manner or in a bubbling manner for inclusion into a liquid.

[Chain Extension Step]

The method for producing carbodiimide in the present embodiment maycomprise a chain extension step of reacting a portion of an isocyanategroup in a carbodiimide compound obtained by the reaction of thealiphatic tertiary isocyanate compound (A) with a chain extender, at atleast one time point among three time points, before the carbodiimideproduction step, during the production step, and after the productionstep, provided that the chain extension step is not necessarilyperformed.

The chain extender may be any organic compound having two or morefunctional groups each reactive with a terminal isocyanate group of thecarbodiimide compound. The organic compound is preferably a polyolhaving two or more hydroxyl groups or a polyamine having two or moreamino groups, more preferably diol or diamine, and further preferably acompound (D-2) represented by general formula (2-2), described below.

The chain extension step may be performed at at least one time pointamong three time points, before the carbodiimide production step, duringthe production step, and after the production step, may be performed atonly any one time point, or may be performed, for example, after theproduction step.

The chain extension step enables the polymerization degree of theresulting carbodiimide compound to be controlled, provided that thechain extension step may be omitted.

<Compound (D-2) Represented by General Formula (2-2)>

The compound (D-2) for use in the present embodiment is represented bythe following general formula (2-2);

wherein R³ is an alkylene group having 2 to 3 carbon atoms; and p is aninteger of 2 to 500.

The compound (D-2) is used as the chain extender, thereby resulting inchain extension of a portion of an end of the aliphatic tertiaryisocyanate compound (A) due to a urethanization reaction of a portion ofan isocyanate group in the aliphatic tertiary isocyanate compound (A)with a hydroxyl group of such a chain extender (D-2). Such an aliphatictertiary isocyanate compound containing a substituent, whose end is thuspartially subjected to chain extension with the chain extender (D-2), isenhanced in reaction rate of the carbodiimidization reaction because aresidue of the compound (D-2) to serves as the phase transfer catalyst.

The compound (D-2) is preferably at least one of polyoxyethylene andpolyoxypropylene.

Such chain extension with the compound (D-2) may be performed at atleast one time point among three time points, before the above-mentionedcarbodiimide production step, during the production step, and after theproduction step, may be performed at only any one time point, or may beperformed, for example, after the production step.

The number average molecular weight of the compound (D-2) is preferably100 or more from the viewpoint of an enhancement in reaction rate of thecarbodiimidization reaction of the tertiary isocyanate group-containingcompound (A), and is preferably 5000 or less from the viewpoints ofhandleability and solubility. The number average molecular weight ismore preferably 100 to 1000, further preferably 100 to 800, stillfurther preferably 200 to 700, still further preferably 250 to 700, andstill further preferably 300 to 600 from the same viewpoints.

The amount of compound (D-2) to be added can be appropriately selecteddepending on the polymerization degree of a carbodiimide compound to beproduced.

When the compound (D-2) is here added, the amount thereof to be added ispreferably 0.01 parts by mass or more, more preferably 0.1 parts by massor more, and further preferably 1.0 parts by mass or more based on 100parts by mass of the aliphatic tertiary isocyanate compound (A), fromthe viewpoint of promotion of the carbodiimide reaction. The amount ofcompound (D-2) to be added is preferably 200 parts by mass or less, morepreferably 50 parts by mass or less, and further preferably 5.0 parts bymass or less based on 100 parts by mass of the aliphatic tertiaryisocyanate compound (A), from an economic viewpoint and from theviewpoint of securement of the concentration of carbodiimide.

<Reaction Conditions>

The reaction temperature in the chain extension step is appropriatelyset depending on the type of the aliphatic tertiary isocyanate compound(A). The detail of the reaction conditions is the same as in the case ofthe end-capping step.

[Adsorption and Removal Step]

The method for producing carbodiimide in the present embodiment maycomprise an adsorption and removal step of performing adsorption andremoval of the organic alkali metal compound (B) having Lewis basicity,with an adsorbent (E), during or after the carbodiimide production step,preferably after the carbodiimide production step. Thus, the organicalkali metal compound (B) having Lewis basicity can be sufficientlyremoved from the resulting carbodiimide compound, provided that theadsorption and removal step may be omitted.

The organic alkali metal compound (B), when used in combination with anantioxidant, may cause coloration, and thus the content of the organicalkali metal compound (B) in the carbodiimide compound is preferably2000 ppm by mass or less, more preferably 1000 ppm by mass or less, andfurther preferably 200 ppm by mass or less.

An adsorption procedure may be any of a stirring and admixing methodinvolving admixing an adsorbent into the carbodiimide compound and thenperforming filtration, and a filtration layer method involving allowingthe carbodiimide compound to be distributed in a filtration layer filledwith an adsorbent, and such an adsorbent may be subjected to nofiltration after admixing thereof with the carbodiimide compound.

<Adsorbent (E)>

The adsorbent (E) for use in the present embodiment is not particularlylimited, and is preferably at least one of a synthetic aluminumsilicate-based adsorbent, synthetic magnesium silicate, an acidiccation-exchange resin, a basic anion-exchange resin, alumina, a silicagel-based adsorbent, a zeolite-based adsorbent, hydrotalcites, amagnesium oxide-aluminum oxide-based solid solution, aluminum hydroxide,magnesium oxide, and an aluminum hydroxide-sodium hydrogen carbonatecoprecipitate (dawsonite), and more preferably at least one of asynthetic aluminum silicate-based adsorbent, a synthetic magnesiumsilicate-based adsorbent, an acidic cation-exchange resin, a basicanion-exchange resin, alumina, a silica gel-based adsorbent, and azeolite-based adsorbent.

The amount of the adsorbent (E) to be added is preferably 50 to 5000parts by mass, more preferably 100 to 1000 parts by mass, furtherpreferably 200 to 1000 parts by mass, and further preferably 400 to 800parts by mass based on 100 parts by mass of the organic alkali metalcompound (B) having Lewis basicity.

<Carbodiimide Compound>

The method for producing a carbodiimide compound according to thepresent embodiment enables a carbodiimide compound to be produced by areaction of an aliphatic tertiary isocyanate compound, at a high yield,even in the case of substantial no use of any organic phosphoruscompound as a carbodiimidization catalyst.

The carbodiimide compound obtained by the method for producing acarbodiimide compound according to the present embodiment preferably hasa purity (content) of 90% by mass or more, and comprises no phospholeneoxides or comprises phospholene oxides at a content of 1 ppm by mass orless.

The purity (content) here means the content of the carbodiimide compoundin an active component of a product obtained by the method for producinga carbodiimide compound according to the present embodiment. The activecomponent here means the total amount of component(s) except for asolvent when the product comprises the solvent, and means the totalamount of the product when the product comprises no solvent. Much thesame is true on a stabilizer and a carbodiimide composition describedbelow.

A carbodiimide compound according to the present embodiment can besuitably used for preventing hydrolysis of a resin. Examples of theresin here include a thermoplastic polyurethane, and such a resin can beadded to a diisocyanate as a raw material of a urethane resin inadvance, and stored, and can be used for production of a urethane resincomprising a stabilizer through no step of adding such a stabilizerafter production of such a urethane resin.

2. Stabilizer

A stabilizer according to the present embodiment is a stabilizercomprising a carbodiimide compound with an aliphatic tertiary isocyanatecompound (A) as a structural unit, and an alkali metal (alkali metalderived from an organic alkali metal compound (B) having Lewisbasicity), and comprising no phospholene oxides or comprisingphospholene oxides at a content of 1 ppm by mass or less.

The stabilizer is useful as a stabilizer for various resins such as athermoplastic resin, or useful for inhibition of hydrolysis. Thestabilizer can be added to any diisocyanate as a raw material of aurethane resin in advance, and stored, and is useful for production of aurethane resin comprising the stabilizer through no step of adding thestabilizer to the urethane resin. The resin is not particularly limited,and examples thereof include polyurethane and thermoplasticpolyurethane.

The aliphatic tertiary isocyanate compound (A) as a structural unit ofthe carbodiimide compound comprised in the stabilizer is suitably thesame as that used in “1. Method for producing carbodiimide compound”described above.

The carbodiimide compound may be end-capped with an end-capping agent asdescribed in “1. Method for producing carbodiimide compound”. Theend-capping agent is suitably the above-mentioned compound (D-1).

The carbodiimide compound may be capped with a chain extender, asdescribed in “1. Method for producing carbodiimide compound”. The chainextender is suitably the above-mentioned compound (D-2).

The content (namely, purity) of the carbodiimide compound with thealiphatic tertiary isocyanate compound (A) as a structural unit in thestabilizer is preferably 80% by mass or more, more preferably 90% bymass or more, further preferably 95% by mass or more, and still furtherpreferably 99% by mass.

The alkali metal comprised in the stabilizer is preferably at least oneof lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs),and francium (Fr), more preferably at least one of lithium (Li), sodium(Na), cesium (Cs), and potassium (K), and further preferably at leastone lithium (Li), sodium (Na), and potassium (K).

The content of the alkali metal in the stabilizer is preferably lessthan 2000 ppm by mass. A content of less than 2000 ppm by mass preventsthe problem of difficulty of use due to interference with an objectmaterial.

The content of the alkali metal in the stabilizer is preferably 10 ppmby mass or more and more preferably 100 ppm by mass or more from theviewpoint of ease of production.

The stabilizer preferably comprises no phospholene oxides or comprisesphospholene oxides at a content of 1 ppm by mass or less.

Therefore, the problem of difficulty of use due to interference ofphospholene oxides with an object material is prevented.

The stabilizer may further comprise the phase transfer catalyst (C).

The content of the phase transfer catalyst (C) in the stabilizer ispreferably 0.1 to 10 parts by mass, more preferably 0.3 to 5 parts bymass, and further preferably 0.5 to 2 parts by mass based on 100 partsby mass of the carbodiimide compound. A content of 10 parts by mass orless prevents troubles such as appearance failure due to bleed-out ofthe phase transfer catalyst and stickiness in use from occurring in useof any of various resins as the stabilizer, and a content of 0.1 partsby mass or more allows an objective reaction promotion effect to befavorable.

The stabilizer is suitably produced by a production method comprising“1. Method for producing carbodiimide compound” described above.

That is, the stabilizer may be produced only by “1. Method for producingcarbodiimide compound” described above, or may be produced through othersubsequent step such as addition of other additive.

3. Carbodiimide Composition

A carbodiimide composition according to the present embodiment is acarbodiimide composition comprising a carbodiimide compound with analiphatic tertiary isocyanate compound (A) as a structural unit, and analkali metal (alkali metal derived from an organic alkali metal compound(B) having Lewis basicity), and comprising no phospholene oxides orcomprising phospholene oxides at a content of 1 ppm by mass or less.

Each component in the carbodiimide composition is the same as in theabove-mentioned stabilizer.

4. Method for Producing Polyurethane

A method for producing a polyurethane according to the presentembodiment is a method for producing a polyurethane, comprising reactinga polyol and a diisocyanate in the presence of a stabilizer to therebyobtain a polyurethane, preferably a thermoplastic polyurethane, whereinthe stabilizer comprises an aliphatic tertiary carbodiimide derived froman aliphatic tertiary isocyanate compound and comprises an alkali metalat a content of less than 2000 ppm by mass.

The amount of the aliphatic tertiary carbodiimide derived from analiphatic tertiary isocyanate compound, to be added, based on the totalamount of 100 parts by mass of the polyol and the diisocyanate ispreferably 0.1 to 2 parts by mass, more preferably 0.5 to 1 part bymass.

The aliphatic tertiary carbodiimide derived from an aliphatic tertiaryisocyanate compound is preferably metered and loaded at a temperature ofpreferably 20 to 50° C., particularly preferably 25 to 35° C., in theform of a liquid in a continuous or batch manner.

The stabilizer here suitably used is any stabilizer described in “2.Stabilizer”.

A method for producing a polyurethane according to another embodiment isa method for producing a polyurethane, comprising reacting a polyol anda diisocyanate in the presence of a stabilizer to thereby obtain apolyurethane, preferably a thermoplastic polyurethane, wherein thestabilizer is a carbodiimide compound produced by the above method forproducing a carbodiimide compound according to the present embodiment.

5. Ester-Based Resin Composition

An ester-based resin composition according to the present embodiment isan ester-based resin composition comprising the above-mentionedcarbodiimide composition and an ester-based resin.

The content of the carbodiimide composition in the ester-based resincomposition is 0.2 to 5.0 parts by mass based on 100 parts by mass ofthe ester-based resin.

An ester-based resin composition according to another embodiment is anester-based resin composition comprising the above-mentioned stabilizerand an ester-based resin. The content of the stabilizer in theester-based resin composition is preferably 0.2 to 5.0 parts by massbased on 100 parts by mass of the ester-based resin.

EXAMPLES

Hereinafter, the present invention will be described with reference toExamples in more detail, but the present invention is not limitedthereto.

Respective evaluations in Examples below were performed according to thefollowing methods.

(1) Infrared (IR) Spectrum Measurement

FTIR-8200PC (manufactured by Shimadzu Corporation) was used.

(2) GPC

RI detector: RID-6A (manufactured by Shimadzu Corporation)

Column: KF-806, KF-804L, KF-804L (manufactured by Showa Denko K.K.)

Developing solvent: tetrahydrofuran (THF) 1 ml/min.

The number average molecular weight (Mn) in terms of the polystyreneequivalent was calculated.

(3) NCO %

A HIRANUMA Automatic Titrator COM-900 (manufactured by HIRANUMA SANGYOCo., Ltd.) and a Tit-Station K-900 (manufactured by HIRANUMA SANGYO Co.,Ltd.) were used, a dibutylamine/toluene solution having a knownconcentration was added, and calculation was made by potentiometrictitration with an aqueous hydrochloric acid solution.

(4) Confirmation of Presence or Absence of Carbodiimidization Catalyst

After 10 g of diphenylmethane diisocyanate and 1 g of the resultingpolycarbodiimide were mixed, and heated with stirring at 100° C. for 1hour, an absorption peak was confirmed immediately after the mixing andafter the mixing and heating, by infrared (IR) spectrum measurement, andthe presence or absence of the carbodiimidization catalyst was confirmedby the presence or absence of peaks (at a wavelength of about 1710 cm⁻¹and a wavelength of about 1411 cm⁻¹) derived from an isocyanuratecompound of the diphenylmethane diisocyanate and the presence or absenceof peaks (at a wavelength of about 2138 cm⁻¹ and a wavelength of about2112 cm⁻¹) derived from the carbodiimide compound.

(Quantitative Determination of Alkali Metal)

Each alkali metal comprised in the carbodiimide compound and thestabilizer was subjected to quantitative determination by the followingoperation according to an inductively coupled plasma (ICP) emissionspectroscopic analysis method.

After 1.00 g of the carbodiimide compound or the stabilizer and 19.00 gof ultrapure water were mixed and left to still stand for 24 hours, anaqueous mixed solution was filtered with a 0.1-μm membrane filter. Thefiltrate thus obtained was subjected to elemental analysis with aninductively coupled plasma (ICP) emission spectroscopic analyzer(product name: ICPS-8100, manufactured by Shimadzu Corporation). Thecontent rate of each alkali metal atom in the carbodiimide compound orthe stabilizer was determined with a calibration curve of such eachalkali metal, based on the difference calculated from the elementalanalysis results obtained and the measurement results of only ultrapurewater.

Example 1

100 g of tetramethylxylylene diisocyanate and 0.5 g of an organic alkalimetal having Lewis basicity (potassium tert-butoxide) as acarbodiimidization catalyst were placed in a 300-ml reaction containerwith a reflux tube and a stirrer and stirred under a nitrogen gas flowat 175° C. to perform a reaction until the result of NCO % measurementwas 3.74%. The synthesis time (time taken for carbodiimidization) was 26hours.

Herein, the NCO % value being 3.74% corresponded to the content (% bymass) of a NCO group in a carbodiimide compound (having a NCO group oneach of both ends) having a polymerization degree of 10 under theassumption of that the carbodiimide compound was produced bydecarboxylation condensation of eleven tetramethylxylylenediisocyanates. Such a value of 3.74% was set as a target value, and theabove-mentioned reaction was performed until the measurement value ofNCO % reached the target value.

The resulting isocyanate-terminated polytetramethylxylylene carbodiimide(average polymerization degree=10) was analyzed, and, as a result, anabsorption peak attributed to a carbodiimide group at a wavelength ofabout 2118 cm⁻¹ was confirmed by infrared (IR) spectrum measurement.

The following could not be confirmed: absorption peaks attributed to anisocyanurate as an isocyanate trimer at absorption wavelengths: awavelength of about 1710 cm⁻¹ and a wavelength of about 1411 cm⁻¹;absorption peaks attributed to a uretdione as an isocyanate dimer atabsorption wavelengths: a wavelength of about 1765 cm⁻¹ and a wavelengthof about 1410 cm⁻¹; and any absorption peak based on other by-product.Furthermore, GPC measurement was performed, and the polystyreneequivalent number average molecular weight was thus 1891.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, thus absorption peaks attributed to anisocyanurate of the diphenylmethane diisocyanate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; were observed, and it was thus confirmed that the catalystremained.

Compounding and synthesis conditions of each raw material are shown inTable 1, and the evaluation results are shown in Table 2. Much the sameis true on the following Examples and Comparative Examples.

Example 2

100 g of 3-isopropenyl-α,α-dimethylbenzyl isocyanate and 0.5 g of anorganic alkali metal having Lewis basicity (potassium tert-butoxide) asa carbodiimidization catalyst were placed in a 300-ml reaction containerwith a reflux tube and a stirrer and stirred under a nitrogen gas flowat 175° C. to perform a reaction until any absorption of an isocyanategroup at a wavelength of 2200 to 2300 cm⁻¹ disappeared in infrared (IR)spectrum measurement (NCO % was 0%). The synthesis time was 45 hours.The resulting di(3-isopropenyl-α,α-dimethylbenzyl)monocarbodiimide wasanalyzed, and, as a result, an absorption peak attributed to acarbodiimide group at a wavelength of about 2118 cm⁻¹ was confirmed byinfrared (IR) spectrum measurement. The following could not beconfirmed: absorption peaks attributed to an isocyanurate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; absorption peaks attributed to a uretdione at absorptionwavelengths: a wavelength of about 1765 cm⁻¹ and a wavelength of about1410 cm⁻¹; and any absorption peak based on other by-product.Furthermore, GPC measurement was performed, and the polystyreneequivalent number average molecular weight was thus 145.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, thus absorption peaks attributed to anisocyanurate of the diphenylmethane diisocyanate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; were observed, and it was thus confirmed that the catalystremained.

Example 3

100 g of tetramethylxylylene diisocyanate and 0.5 g of an organic alkalimetal compound having Lewis basicity (sodium ethoxide) as acarbodiimidization catalyst were placed in a 300-ml reaction containerwith a reflux tube and a stirrer and stirred under a nitrogen gas flowat 175° C. to perform a reaction until the result of NCO % measurementwas 3.74%. The synthesis time was 21 hours. The resulting isocyanate-endpolytetramethylxylylene carbodiimide (average polymerization degree=10)was analyzed, and as a result, an absorption peak attributed to acarbodiimide group at a wavelength of about 2118 cm⁻¹ was confirmed byinfrared (IR) spectrum measurement. The following could not beconfirmed: absorption peaks attributed to an isocyanurate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; absorption peaks attributed to a uretdione at absorptionwavelengths: a wavelength of about 1765 cm⁻¹ and a wavelength of about1410 cm⁻¹; and any absorption peak based on other by-product.Furthermore, GPC measurement was performed, and the polystyreneequivalent number average molecular weight was thus 1886.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, thus absorption peaks attributed to anisocyanurate of the diphenylmethane diisocyanate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; were observed, and it was thus confirmed that the catalystremained.

Example 4

100 g of tetramethylxylylene diisocyanate and 0.5 g of an organic alkalimetal having Lewis basicity (lithium diisopropylamide) as acarbodiimidization catalyst were placed in a 300-ml reaction containerwith a reflux tube and a stirrer and stirred under a nitrogen gas flowat 175° C. to perform a reaction until the result of NCO % measurementwas 3.74%. The synthesis time was 10 hours. The resultingisocyanate-terminated polytetramethylxylylene carbodiimide (averagepolymerization degree=10) was analyzed, and, as a result, an absorptionpeak attributed to a carbodiimide group at a wavelength of about 2118cm⁻¹ was confirmed by infrared (IR) spectrum measurement. The followingcould not be confirmed: absorption peaks attributed to an isocyanurateat absorption wavelengths: a wavelength of about 1710 cm⁻¹ and awavelength of about 1411 cm⁻¹; absorption peaks attributed to auretdione at absorption wavelengths: a wavelength of about 1765 cm⁻¹ anda wavelength of about 1410 cm⁻¹; and any absorption peak based on otherby-product. Furthermore, GPC measurement was performed, and thepolystyrene equivalent number average molecular weight was thus 1899.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, thus absorption peaks attributed to anisocyanurate of the diphenylmethane diisocyanate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; were observed, and it was thus confirmed that the catalystremained.

Example 5

100 g of tetramethylxylylene diisocyanate and 0.5 g of an organic alkalimetal having Lewis basicity (cesium acetate) as a carbodiimidizationcatalyst were placed in a 300-ml reaction container with a reflux tubeand a stirrer and stirred under a nitrogen gas flow at 175° C. toperform a reaction until the result of NCO % measurement was 3.74%. Thesynthesis time was 21 hours. The resulting isocyanate-terminatedpolytetramethylxylylene carbodiimide (average polymerization degree=10)was analyzed, and, as a result, an absorption peak attributed to acarbodiimide group at a wavelength of about 2118 cm⁻¹ was confirmed byinfrared (IR) spectrum measurement. The following could not beconfirmed: absorption peaks attributed to an isocyanurate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; absorption peaks attributed to a uretdione at absorptionwavelengths: a wavelength of about 1765 cm⁻¹ and a wavelength of about1410 cm⁻¹; and any absorption peak based on other by-product.Furthermore, GPC measurement was performed, and the polystyreneequivalent number average molecular weight was thus 1904.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, thus absorption peaks attributed to anisocyanurate of the diphenylmethane diisocyanate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; were observed, and it was thus confirmed that the catalystremained.

Example 6

100 g of tetramethylxylylene diisocyanate, 0.5 g of an organic alkalimetal compound having Lewis basicity (potassium acetate) as acarbodiimidization catalyst, and 1.0 g of a phase transfer catalyst(18-crown 6-ether) were placed in a 300-ml reaction container with areflux tube and a stirrer and stirred under a nitrogen gas flow at 175°C. to perform a reaction until the result of NCO % measurement was3.74%. The synthesis time was 33 hours. The resultingisocyanate-terminated polytetramethylxylylene carbodiimide (averagepolymerization degree=10) was analyzed, and, as a result, an absorptionpeak attributed to a carbodiimide group at a wavelength of about 2118cm⁻¹ was confirmed by infrared (IR) spectrum measurement. The followingcould not be confirmed: absorption peaks attributed to an isocyanurateat absorption wavelengths: a wavelength of about 1710 cm⁻¹ and awavelength of about 1411 cm⁻¹; absorption peaks attributed to auretdione at absorption wavelengths: a wavelength of about 1765 cm⁻¹ anda wavelength of about 1410 cm⁻¹; and any absorption peak based on otherby-product. Furthermore, GPC measurement was performed, and thepolystyrene equivalent number average molecular weight was thus 1955.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, thus absorption peaks attributed to anisocyanurate of the diphenylmethane diisocyanate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; were observed, and it was thus confirmed that the catalystremained.

Example 7

100 g of tetramethylxylylene diisocyanate, 0.5 g of an organic alkalimetal compound having Lewis basicity (potassium tert-butoxide) as acarbodiimidization catalyst, and 1.0 g of a phase transfer catalyst(tetrabutylammonium-2-ethylhexanoate) were placed in a 300-ml reactioncontainer with a reflux tube and a stirrer and stirred under a nitrogengas flow at 175° C. to perform a reaction until the result of NCO %measurement was 3.74%. The synthesis time was 20 hours. The resultingisocyanate-terminated polytetramethylxylylene carbodiimide (averagepolymerization degree=10) was analyzed, and, as a result, an absorptionpeak attributed to a carbodiimide group at a wavelength of about 2118cm⁻¹ was confirmed by infrared (IR) spectrum measurement. The followingcould not be confirmed: absorption peaks attributed to an isocyanurateat absorption wavelengths: a wavelength of about 1710 cm⁻¹ and awavelength of about 1411 cm⁻¹; absorption peaks attributed to auretdione at absorption wavelengths: a wavelength of about 1765 cm⁻¹ anda wavelength of about 1410 cm⁻¹; and any absorption peak based on otherby-product. Furthermore, GPC measurement was performed, and thepolystyrene equivalent number average molecular weight was thus 1910.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, thus absorption peaks attributed to anisocyanurate of the diphenylmethane diisocyanate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; were observed, and it was thus confirmed that the catalystremained.

Example 8

100 g of tetramethylxylylene diisocyanate, 0.5 g of an organic alkalimetal compound having Lewis basicity (potassium tert-butoxide) as acarbodiimidization catalyst, and 1.0 g of a phase transfer catalyst(18-crown 6-ether) were placed in a 300-ml reaction container with areflux tube and a stirrer and stirred under a nitrogen gas flow at 175°C. to perform a reaction until the result of NCO % measurement was3.74%. The synthesis time was 2 hours. The resultingisocyanate-terminated polytetramethylxylylene carbodiimide (averagepolymerization degree=10) was analyzed, and, as a result, an absorptionpeak attributed to a carbodiimide group at a wavelength of about 2118cm⁻¹ was confirmed by infrared (IR) spectrum measurement. The followingcould not be confirmed: absorption peaks attributed to an isocyanurateat absorption wavelengths: a wavelength of about 1710 cm⁻¹ and awavelength of about 1411 cm⁻¹; absorption peaks attributed to auretdione at absorption wavelengths: a wavelength of about 1765 cm⁻¹ anda wavelength of about 1410 cm⁻¹; and any absorption peak based on otherby-product. Furthermore, GPC measurement was performed, and thepolystyrene equivalent number average molecular weight was thus 1889.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, thus absorption peaks attributed to anisocyanurate of the diphenylmethane diisocyanate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; were observed, and it was thus confirmed that the catalystremained.

Example 9

100 g of tetramethylxylylene diisocyanate, 0.5 g of an organic alkalimetal compound having Lewis basicity (sodium ethoxide) as acarbodiimidization catalyst, and 1.0 g of a phase transfer catalyst(15-crown 5-ether) were placed in a 300-ml reaction container with areflux tube and a stirrer and stirred under a nitrogen gas flow at 175°C. to perform a reaction until the result of NCO % measurement was3.74%. The synthesis time was 2 hours. The resultingisocyanate-terminated polytetramethylxylylene carbodiimide (averagepolymerization degree=10) was analyzed, and, as a result, an absorptionpeak attributed to a carbodiimide group at a wavelength of about 2118cm⁻¹ was confirmed by infrared (IR) spectrum measurement. The followingcould not be confirmed: absorption peaks attributed to an isocyanurateat absorption wavelengths: a wavelength of about 1710 cm⁻¹ and awavelength of about 1411 cm⁻¹; absorption peaks attributed to auretdione at absorption wavelengths: a wavelength of about 1765 cm⁻¹ anda wavelength of about 1410 cm⁻¹; and any absorption peak based on otherby-product. Furthermore, GPC measurement was performed, and thepolystyrene equivalent number average molecular weight was thus 1897.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, thus absorption peaks attributed to anisocyanurate of the diphenylmethane diisocyanate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; were observed, and it was thus confirmed that the catalystremained.

Example 10

100 g of tetramethylxylylene diisocyanate, 0.5 g of an organic alkalimetal compound having Lewis basicity (potassium tert-butoxide) as acarbodiimidization catalyst, and 1.0 g of a phase transfer catalyst(end-capped polyethylene glycol:polyoxyethylene dimethyl ether, numberaverage molecular weight: 550) were placed in a 300-ml reactioncontainer with a reflux tube and a stirrer and stirred under a nitrogengas flow at 175° C. to perform a reaction until a time point where theresult of NCO % measurement was 3.74%. The synthesis time was 11 hours.An isocyanate-terminated polytetramethylxylylene carbodiimide (averagepolymerization degree=10) was obtained. An absorption peak attributed toa carbodiimide group at a wavelength of about 2118 cm⁻¹ was confirmed byinfrared (IR) spectrum measurement. The following could not beconfirmed: absorption peaks attributed to an isocyanurate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; absorption peaks attributed to a uretdione at absorptionwavelengths: a wavelength of about 1765 cm⁻¹ and a wavelength of about1410 cm⁻¹; and any absorption peak based on other by-product.Furthermore, GPC measurement was performed, and the polystyreneequivalent number average molecular weight was thus 1922.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, thus absorption peaks attributed to anisocyanurate of the diphenylmethane diisocyanate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; were observed, and it was thus confirmed that the catalystremained.

Example 11

100 g of tetramethylxylylene diisocyanate, 0.5 g of an organic alkalimetal compound having Lewis basicity (cesium acetate) as acarbodiimidization catalyst, and 1.0 g of a phase transfer catalyst(end-capped polyethylene glycol:polyoxyethylene dimethyl ether, numberaverage molecular weight: 550) were placed in a 300-ml reactioncontainer with a reflux tube and a stirrer and stirred under a nitrogengas flow at 175° C. to perform a reaction until a time point where theresult of NCO % measurement was 3.74%. The synthesis time was 10 hours.An isocyanate-terminated polytetramethylxylylene carbodiimide (averagepolymerization degree=10) was obtained. An absorption peak attributed toa carbodiimide group at a wavelength of about 2118 cm⁻¹ was confirmed byinfrared (IR) spectrum measurement. The following could not beconfirmed: absorption peaks attributed to an isocyanurate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; absorption peaks attributed to a uretdione at absorptionwavelengths: a wavelength of about 1765 cm⁻¹ and a wavelength of about1410 cm⁻¹; and any absorption peak based on other by-product.Furthermore, GPC measurement was performed, and the polystyreneequivalent number average molecular weight was thus 1931.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, thus absorption peaks attributed to anisocyanurate of the diphenylmethane diisocyanate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; were observed, and it was thus confirmed that the catalystremained.

Example 12

100 g of tetramethylxylylene diisocyanate and 1.0 g of polyoxyethylenemonomethyl ether having a function like that of a phase transfercatalyst and having a number average molecular weight of 550 were placedin a 300-ml reaction container with a reflux tube and a stirrer andstirred under a nitrogen gas flow at 175° C. for 1 hour to allow ahydroxyl group as an end group of the polyoxyethylene monomethyl etherto react with the tetramethylxylylene diisocyanate by a urethanizationreaction, and thereafter 0.5 g of an organic alkali metal compoundhaving Lewis basicity (potassium tert-butoxide) as a carbodiimidizationcatalyst was loaded thereto to perform a reaction until a time pointwhere the result of NCO % measurement was 3.66%. The synthesis time was11 hours.

An isocyanate-terminated polytetramethylxylylene carbodiimide (averagepolymerization degree=10) was obtained (provided that the carbodiimidewas partially end-capped with the polyoxyethylene monomethyl ether). Anabsorption peak attributed to a carbodiimide group at a wavelength ofabout 2118 cm⁻¹ was confirmed by infrared (IR) spectrum measurement. Thefollowing could not be confirmed: absorption peaks attributed to anisocyanurate at absorption wavelengths: a wavelength of about 1710 cm⁻¹and a wavelength of about 1411 cm⁻¹; absorption peaks attributed to auretdione at absorption wavelengths: a wavelength of about 1765 cm⁻¹ anda wavelength of about 1410 cm⁻¹; and any absorption peak based on otherby-product. Furthermore, GPC measurement was performed, and thepolystyrene equivalent number average molecular weight was thus 1924.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, thus absorption peaks attributed to anisocyanurate of the diphenylmethane diisocyanate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; were observed, and it was thus confirmed that the catalystremained.

Example 13

100 g of tetramethylxylylene diisocyanate and 41 g of polyoxyethylenemonomethyl ether (average molecular weight: 550) having a function likethat of a phase transfer catalyst were placed in a 300-ml reactioncontainer with a reflux tube and a stirrer and stirred under a nitrogengas flow at 175° C. for 1 hour to react a hydroxyl group as an end groupof the polyoxyethylene monomethyl ether with the tetramethylxylylenediisocyanate by a urethanization reaction. (Molar ratio betweentetramethylxylylene diisocyanate and polyoxyethylene monomethyl ether:11:2.) Subsequently, 0.5 g of an organic alkali metal compound havingLewis basicity (potassium tert-butoxide) as a carbodiimidizationcatalyst was loaded thereto and stirred to perform a reaction until anyabsorption of an isocyanate group at a wavelength of 2200 to 2300 cm⁻¹disappeared in infrared (IR) spectrum measurement. The synthesis timewas 8 hours. The resulting polyoxyethylene monomethyl ether-terminatedpolycarbodiimide (average polymerization degree: 10) was analyzed, and,as a result, an absorption peak attributed to a carbodiimide group at awavelength of about 2118 cm⁻¹ was confirmed by infrared (IR) spectrummeasurement. The following could not be confirmed: absorption peaksattributed to an isocyanurate at absorption wavelengths: a wavelength ofabout 1710 cm⁻¹ and a wavelength of about 1411 cm⁻¹; absorption peaksattributed to a uretdione at absorption wavelengths: a wavelength ofabout 1765 cm⁻¹ and a wavelength of about 1410 cm⁻¹; and any absorptionpeak based on other by-product. Furthermore, GPC measurement wasperformed, and the polystyrene equivalent number average molecularweight was thus 2320.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, thus absorption peaks attributed to anisocyanurate of the diphenylmethane diisocyanate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; were observed, and it was thus confirmed that the catalystremained.

Example 14

100 g of tetramethylxylylene diisocyanate and 41 g of polyoxyethylenemonomethyl ether (average molecular weight: 550) having a function likethat of a phase transfer catalyst were placed in a 300-ml reactioncontainer with a reflux tube and a stirrer and stirred under a nitrogengas flow at 175° C. for 1 hour to react a hydroxyl group as an end groupof the polyoxyethylene monomethyl ether with the tetramethylxylylenediisocyanate by a urethanization reaction. (Molar ratio betweentetramethylxylylene diisocyanate and polyoxyethylene monomethyl ether:11:2.) Subsequently, 0.5 g of an organic alkali metal compound havingLewis basicity (potassium tert-butoxide) as a carbodiimidizationcatalyst and 1.0 g of a phase transfer catalyst(tetrabutylammonium-2-ethylhexanoate) were loaded thereto and stirred toperform a reaction until any absorption of an isocyanate group at awavelength of 2200 to 2300 cm⁻¹ disappeared in infrared (IR) spectrummeasurement. The synthesis time was 4.5 hours. The resultingpolyoxyethylene monomethyl ether-terminated polycarbodiimide (averagepolymerization degree: 10) was analyzed, and, as a result, an absorptionpeak attributed to a carbodiimide group at a wavelength of about 2118cm⁻¹ was confirmed by infrared (IR) spectrum measurement. The followingcould not be confirmed: absorption peaks attributed to an isocyanurateat absorption wavelengths: a wavelength of about 1710 cm⁻¹ and awavelength of about 1411 cm⁻¹; absorption peaks attributed to auretdione at absorption wavelengths: a wavelength of about 1765 cm⁻¹ anda wavelength of about 1410 cm⁻¹; and any absorption peak based on otherby-product. Furthermore, GPC measurement was performed, and thepolystyrene equivalent number average molecular weight was thus 2350.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, thus absorption peaks attributed to anisocyanurate of the diphenylmethane diisocyanate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; were observed, and it was thus confirmed that the catalystremained.

Example 15

100 g of tetramethylxylylene diisocyanate and 41 g of polyoxyethylenemonomethyl ether (average molecular weight: 550) having a function likethat of a phase transfer catalyst were placed in a 300-ml reactioncontainer with a reflux tube and a stirrer and stirred under a nitrogengas flow at 175° C. for 1 hour to react a hydroxyl group as an end groupof the polyoxyethylene monomethyl ether with the tetramethylxylylenediisocyanate by a urethanization reaction. (Molar ratio betweentetramethylxylylene diisocyanate and polyoxyethylene monomethyl ether:11:2.) Subsequently, 0.5 g of an organic alkali metal compound havingLewis basicity (potassium tert-butoxide) as a carbodiimidizationcatalyst and 1.0 g of a phase transfer catalyst (18-crown 6-ether) wereloaded thereto and stirred to perform a reaction until any absorption ofan isocyanate group at a wavelength of 2200 to 2300 cm⁻¹ disappeared ininfrared (IR) spectrum measurement. The synthesis time was 4.5 hours.The resulting polyoxyethylene monomethyl ether-terminatedpolycarbodiimide (average polymerization degree: 10) was analyzed, and,as a result, an absorption peak attributed to a carbodiimide group at awavelength of about 2118 cm⁻¹ was confirmed by infrared (IR) spectrummeasurement. The following could not be confirmed: absorption peaksattributed to an isocyanurate at absorption wavelengths: a wavelength ofabout 1710 cm⁻¹ and a wavelength of about 1411 cm⁻¹; absorption peaksattributed to a uretdione at absorption wavelengths: a wavelength ofabout 1765 cm⁻¹ and a wavelength of about 1410 cm⁻¹; and any absorptionpeak based on other by-product. Furthermore, GPC measurement wasperformed, and the polystyrene equivalent number average molecularweight was thus 2385.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, thus absorption peaks attributed to anisocyanurate of the diphenylmethane diisocyanate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; were observed, and it was thus confirmed that the catalystremained.

Example 16

100 g of tetramethylxylylene diisocyanate and 41 g of polyoxyethylenemonomethyl ether (average molecular weight: 550) having a function likethat of a phase transfer catalyst were placed in a 300-ml reactioncontainer with a reflux tube and a stirrer and stirred under a nitrogengas flow at 175° C. for 1 hour to react a hydroxyl group as an end groupof the polyoxyethylene monomethyl ether with the tetramethylxylylenediisocyanate by a urethanization reaction. (Molar ratio betweentetramethylxylylene diisocyanate and polyoxyethylene monomethyl ether:11:2.) Subsequently, 0.5 g of an organic alkali metal compound havingLewis basicity (potassium tert-butoxide) as a carbodiimidizationcatalyst and 1.0 g of a phase transfer catalyst(tetrabutylammonium-2-ethylhexanoate) were loaded thereto and stirred toperform a reaction until any absorption of an isocyanate group at awavelength of 2200 to 2300 cm⁻¹ disappeared in infrared (IR) spectrummeasurement. The synthesis time was 4.5 hours. Thereafter, 2.5 g of“Kyowaad 600S” (manufactured by Kyowa Chemical Industry Co., Ltd.:2MgO.6SiO₂.mH₂O) as a synthetic magnesium silicate-based adsorbent wasloaded in the reaction container, and stirred under a nitrogen gas flowat 150° C. for 2 hours. Next, suction filtration was performed with aglass suction filter, and polyoxyethylene monomethyl ether-terminatedpolycarbodiimide (average polymerization degree: 10) after catalystadsorption was obtained. The resulting polyoxyethylene monomethylether-terminated polycarbodiimide (average polymerization degree: 10)was analyzed, and, as a result, an absorption peak attributed to acarbodiimide group at a wavelength of about 2118 cm⁻¹ was confirmed byinfrared (IR) spectrum measurement. The following could not beconfirmed: absorption peaks attributed to an isocyanurate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; absorption peaks attributed to a uretdione at absorptionwavelengths: a wavelength of about 1765 cm⁻¹ and a wavelength of about1410 cm⁻¹; and any absorption peak based on other by-product.Furthermore, GPC measurement was performed, and the polystyreneequivalent number average molecular weight was thus 2360.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, and no change in absorption peak was thusconfirmed immediately after the mixing and after the mixing and heatingand sufficient removal of the catalyst was confirmed.

Reference Example 1

100 g of tetramethylxylylene diisocyanate and 0.5 g of3-methyl-1-phenyl-2-phospholene-1-oxide being a phosphorus compound as acarbodiimidization catalyst were placed in a 300-ml reaction containerwith a reflux tube and a stirrer and stirred under a nitrogen gas flowat 175° C. to perform a reaction until the result of NCO % measurementwas 3.74%. The synthesis time was 26 hours. The resultingisocyanate-terminated polytetramethylxylylene carbodiimide (averagepolymerization degree=10) was analyzed, and, as a result, an absorptionpeak attributed to a carbodiimide group at a wavelength of about 2118cm⁻¹ was confirmed by infrared (IR) spectrum measurement. The followingcould not be confirmed: absorption peaks attributed to an isocyanurateat absorption wavelengths: a wavelength of about 1710 cm⁻¹ and awavelength of about 1411 cm⁻¹; absorption peaks attributed to auretdione at absorption wavelengths: a wavelength of about 1765 cm⁻¹ anda wavelength of about 1410 cm⁻¹; and any absorption peak based on otherby-product. Furthermore, GPC measurement was performed, and thepolystyrene equivalent number average molecular weight was thus 1896.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, and it was thus confirmed that the catalystremained, because decarboxylation due to carbodiimidization ofdiphenylmethane diisocyanate was observed during heating and absorptionpeaks at an absorption wavelength of 2138 cm⁻¹ and a wavelength of about2112 cm⁻¹ were observed by infrared (IR) spectrum measurement.

Reference Example 2

100 g of tetramethylxylylene diisocyanate and 0.5 g of3-methyl-1-phenyl-2-phospholene-1-oxide being a phosphorus compound as acarbodiimidization catalyst were placed in a 300-ml reaction containerwith a reflux tube and a stirrer and stirred under a nitrogen gas flowat 195° C. to perform a reaction until a time point where the result ofNCO % measurement was 3.74%. The synthesis time was 12 hours. Theresulting isocyanate-terminated polytetramethylxylylene carbodiimide(average polymerization degree=10) was analyzed, and, as a result, anabsorption peak attributed to a carbodiimide group at a wavelength ofabout 2118 cm⁻¹ was confirmed by infrared (IR) spectrum measurement. Thefollowing could not be confirmed: absorption peaks attributed to anisocyanurate at absorption wavelengths: a wavelength of about 1710 cm⁻¹and a wavelength of about 1411 cm⁻¹; absorption peaks attributed to auretdione at absorption wavelengths: a wavelength of about 1765 cm⁻¹ anda wavelength of about 1410 cm⁻¹; and any absorption peak based on otherby-product. Furthermore, GPC measurement was performed and thepolystyrene equivalent number average molecular weight was thus 1020,and it was thus confirmed that isocyanate by itself was decomposed undera high temperature and no carbodiimidization reaction smoothlyprogressed.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, and it was thus confirmed that the catalystremained, because decarboxylation due to carbodiimidization ofdiphenylmethane diisocyanate was observed during heating and absorptionpeaks at an absorption wavelength of 2138 cm⁻¹ and a wavelength of about2112 cm⁻¹ were observed by infrared (IR) spectrum measurement.

Comparative Example 1

100 g of hexamethylene diisocyanate (primary isocyanate) and 0.5 g of anorganic alkali metal compound having Lewis basicity (potassiumtert-butoxide) as a carbodiimidization catalyst were placed in a 300-mlreaction container with a reflux tube and a stirrer and stirred under anitrogen gas flow at 175° C., but the content was gelated at a timepoint after a lapse of 3 hours. The resulting reaction product wasanalyzed by infrared (IR) spectrum measurement, and, as a result, anabsorption peak attributed to a carbodiimide group at a wavelength ofabout 2125 cm⁻¹ and absorption peaks attributed to an isocyanurate groupat a wavelength of about 1710 cm⁻¹ and a wavelength of about 1411 cm⁻¹were confirmed. The resulting substance was gelated and could not bethus subjected to GPC measurement.

The presence or absence of the carbodiimidization catalyst (alkalimetal) could not also be confirmed because the resulting substance wasgelated and could not be thus subjected to measurement.

Comparative Example 2

100 g of 4,4′-dicyclohexylmethane diisocyanate (secondary isocyanate)and 0.5 g of an organic alkali metal compound having Lewis basicity(potassium tert-butoxide) as a carbodiimidization catalyst were placedin a 300-ml reaction container with a reflux tube and a stirrer andstirred under a nitrogen gas flow at 175° C., but the content wasgelated at a time point after a lapse of 3 hours. The resulting reactionproduct was analyzed by infrared (IR) spectrum measurement, and, as aresult, an absorption peak attributed to a carbodiimide group at awavelength of about 2120 cm⁻¹ and absorption peaks attributed to anisocyanurate group at a wavelength of about 1710 cm⁻¹ and a wavelengthof about 1411 cm⁻¹ were confirmed. The resulting substance was gelatedand could not be thus subjected to GPC measurement.

The presence or absence of the carbodiimidization catalyst (alkalimetal) could not also be confirmed because the resulting substance wasgelated and could not be thus subjected to measurement.

Comparative Example 3

100 g of phenylisocyanate and 0.5 g of an organic alkali metal compoundhaving Lewis basicity (potassium tert-butoxide) as a carbodiimidizationcatalyst were placed in a 300-ml reaction container with a reflux tubeand a stirrer and stirred under a nitrogen gas flow at 120° C. toperform a reaction until any absorption of an isocyanate group at awavelength of 2200 to 2300 cm⁻¹ disappeared in infrared (IR) spectrummeasurement. The synthesis time was 0.5 hours. The resulting reactionproduct was analyzed by infrared (IR) spectrum measurement, and, as aresult, absorption peaks attributed to a carbodiimide group at awavelength of about 2121 cm⁻¹ and a wavelength of about 2102 cm⁻¹ couldnot be confirmed and absorption peaks attributed to an isocyanurategroup at a wavelength of about 1710 cm⁻¹ and a wavelength of about 1411cm⁻¹ were confirmed. The resulting substance was insoluble in a THFsolvent, and could not be thus subjected to molecular weight measurementby GPC.

The presence or absence of the carbodiimidization catalyst (alkalimetal) could not also be determined because the resulting substance wasinsoluble in diphenylmethane diisocyanate and could not be thussubjected to measurement.

Reference Example 3

100 g of tetramethylxylylene diisocyanate and 41 g of polyoxyethylenemonomethyl ether (average molecular weight: 550) were placed in a 300-mlreaction container with a reflux tube and a stirrer and stirred under anitrogen gas flow at 175° C. for 1 hour to react a hydroxyl group as anend group of the polyoxyethylene monomethyl ether with thetetramethylxylylene diisocyanate by a urethanization reaction. (Molarratio between tetramethylxylylene diisocyanate and polyoxyethylenemonomethyl ether: 11:2.) Subsequently, 0.5 g of3-methyl-1-phenyl-2-phospholene-1-oxide being a phosphorus compound as acarbodiimidization catalyst was loaded thereto and stirred to perform areaction until any absorption of an isocyanate group at a wavelength of2200 to 2300 cm⁻¹ disappeared in infrared (IR) spectrum measurement. Thesynthesis time was 52 hours. The resulting polyoxyethylene monomethylether-terminated polycarbodiimide (average polymerization degree: 10)was analyzed, and, as a result, an absorption peak attributed to acarbodiimide group at a wavelength of about 2118 cm⁻¹ was confirmed byinfrared (IR) spectrum measurement. The following could not beconfirmed: absorption peaks attributed to an isocyanurate at absorptionwavelengths: a wavelength of about 1710 cm⁻¹ and a wavelength of about1411 cm⁻¹; absorption peaks attributed to a uretdione at absorptionwavelengths: a wavelength of about 1765 cm⁻¹ and a wavelength of about1410 cm⁻¹; and any absorption peak based on other by-product.Furthermore, GPC measurement was performed, and the polystyreneequivalent number average molecular weight was thus 2377.

The presence or absence of the carbodiimidization catalyst (alkalimetal) was confirmed, and it was thus confirmed that the catalystremained, because decarboxylation due to carbodiimidization ofdiphenylmethane diisocyanate was observed during heating and absorptionpeaks at an absorption wavelength of 2138 cm⁻¹ and a wavelength of about2112 cm⁻¹ were observed by infrared (IR) spectrum measurement.

Comparative Example 4

100 g of tetramethylxylylene diisocyanate and 0.5 g of an alkali earthmetal compound having Lewis basicity (magnesium ethoxide) as acarbodiimidization catalyst were placed in a 300-ml reaction containerwith a reflux tube and a stirrer and stirred under a nitrogen gas flowat 175° C. for 26 hours, and the NCO % was measured and was 34.20%.

The resulting content was analyzed, and, as a result, an absorption peakattributed to a carbodiimide group at a wavelength of about 2118 cm⁻¹could not be confirmed by infrared (IR) spectrum measurement. Thefollowing could not also be confirmed: absorption peaks attributed to anisocyanurate at absorption wavelengths: a wavelength of about 1710 cm⁻¹and a wavelength of about 1411 cm⁻¹; absorption peaks attributed to auretdione at absorption wavelengths: a wavelength of about 1765 cm⁻¹ anda wavelength of about 1410 cm⁻¹; and any absorption peak based on otherby-product.

Gas chromatograph mass spectrometry (GC-MS)

Each carbodiimide compound obtained in Examples, Comparative Examples,and Reference Examples was subjected to quantitative analysis by gaschromatograph mass spectrometry (GC-MS) in the following conditions. Theresults are shown in Table 2.

[Measurement Conditions of GC-MS]

Column: HP-5 (manufactured by Agilent Technologies, inner diameter: 0.32mm, thickness: 0.25 μm, length: 30 m)

Carrier gas: helium, 1.0 mL/min

Injection conditions: 250° C., split ratio: 1/50

Detection conditions: FID system, 220° C.

Column temperature conditions: retention at 40° C. for 5 minutes andthen temperature rise to 350° C. at 10° C./min

Ionization mode: EI

Temperature of ion source: 230° C.

Temperature of interface: 350° C.

TABLE 1 Isocyanate (A) Tertiary Other than tertiary isocyanateCarbodiimidization catalyst isocyanate Primary Secondary Aromatic (B)Phosphorus TMXDI TMI HDI HMDI Ph-Iso PTB EtONa LDA CsAc KAc EtOMg MPO(9) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) (g) Example 1 100 0.5Example 2 100 0.5 Example 3 100 0.5 Example 4 100 0.5 Example 5 100 0.5Example 6 100 0.5 Example 7 100 0.5 Example 8 100 0.5 Example 9 100 0.5Example 10 100 0.5 Example 11 100 0.5 Example 12 100 0.5 Example 13 1000.5 Example 14 100 0.5 Example 15 100 0.5 Example 16 100 0.5 Reference100 0.5 Example 1 Reference 100 0.5 Example 2 Comparative 100 0.5Example 1 Comparative 100 0.5 Example 2 Comparative 100 0.5 Example 3Reference 100 0.5 Example 3 Comparative 100 0.5 Example 4 Phase transfercatalyst End- (C) capping Synthesis conditions PEG agent AdsorbentSynthesis Synthesis 18- 15- end- (D-1) (E) temperature time Crown Crown18X capped MP550 600S (° C.) (hr) (g) (g) (g) (g) (g) (g) (° C.) (hr)Example 1 175 26 Example 2 175 45 Example 3 175 21 Example 4 175 10Example 5 175 21 Example 6 1 175 33 Example 7 1 175 20 Example 8 1 175 2Example 9 1 175 2 Example 10 1 175 11 Example 11 1 175 10 Example 12 1175 11 Example 13 41 175 8 Example 14 1 41 175 4.5 Example 15 1 41 1754.5 Example 16 1 41 2.5 175 4.5 Reference 175 26 Example 1 Reference 19512 Example 2 Comparative 175 Gelation Example 1 Comparative 175 GelationExample 2 Comparative 120 0.5 Example 3 Reference 41 175 52 Example 3Comparative 175 26 Example 4 Notations in Table 1 are as follows. TMXDI:tetramethylxylylene diisocyanate TMI: 3-isopropenyl-α,α-dimethylbenzylisocyanate HDI: hexamethylene diisocyanate HMDI:4,4′-dicyclohexylmethane diisocyanate Ph-Iso: phenylisocyanate PTB:potassium tert-butoxide EtONa: sodium ethoxide LDA: lithiumdiisopropylamide sAc: cesium acetate EtOMg: magnesium ethoxide KAc:potassium acetate MPO: 3-methyl-1-phenyl-2-phospholene-1-oxide 18-Crown:18-crown 6-ether 15-Crown: 15-crown 5-ether 18X:tetrabutylammonium-2-ethylhexanoate PEG end-capped: polyoxyethylenedimethyl ether (number average molecular weight 550) MP550:polyoxyethylene monomethyl ether (number average molecular weight: 550)600S: 2MgO•6SiO₂•mH₂O

TABLE 2 Evaluation results Presence Amount of Amount of or absence ofcarbodiimidization carbodiimidization Average absorption catalyst(alkali catalyst (phospholene Determination by FT-IR polymer- wavelengthmetal) remaining oxides) remaining Carbodi- NCO ization with respect incarbodiimide in carbodiimide imide Dimer Trimer (%) degree Mn toisocyanurate obtained (*1) obtained (*1) Example 1 Presence AbsenceAbsence 3.74 10 1891 Presence 1877 ppm (as K) Not detected (*2) Example2 Presence Absence Absence 0  1  145 Presence 1991 ppm (as K) Notdetected (*2) Example 3 Presence Absence Absence 3.74 10 1886 Presence1866 ppm (as Na) Not detected (*2) Example 4 Presence Absence Absence3.74 10 1899 Presence 1796 ppm (as Li) Not detected (*2) Example 5Presence Absence Absence 3.74 10 1904 Presence 1955 ppm (as Cs) Notdetected (*2) Example 6 Presence Absence Absence 3.74 10 1955 Presence1807 ppm (as K) Not detected (*2) Example 7 Presence Absence Absence3.74 10 1910 Presence 1844 ppm (as K) Not detected (*2) Example 8Presence Absence Absence 3.74 10 1889 Presence 1811 ppm (as K) Notdetected (*2) Example 9 Presence Absence Absence 3.74 10 1897 Presence1845 ppm (as Na) Not detected (*2) Example 10 Presence Absence Absence3.74 10 1922 Presence 1827 ppm (as K) Not detected (*2) Example 11Presence Absence Absence 3.74 10 1931 Presence 1987 ppm (as Cs) Notdetected (*2) Example 12 Presence Absence Absence 3.66 10 1924 Presence1853 ppm (as K) Not detected (*2) Example 13 Presence Absence Absence 010 2320 Presence 1356 ppm (as K) Not detected (*2) Example 14 PresenceAbsence Absence 0 10 2350 Presence 1320 ppm (as K) Not detected (*2)Example 15 Presence Absence Absence 0 10 2385 Presence 1239 ppm (as K)Not detected (*2) Example 16 Presence Absence Absence 0 10 2360 Absence155 ppm (as K) Not detected (*2) Reference Presence Absence Absence 3.7410 1896 Absence 100 ppm or less 100 ppm or more Example 1 (as alkalimetal) (as phospholene oxides) Reference Presence Absence Absence 3.7410 1020 Absence 100 ppm or less 100 ppm or more Example 2 (as alkalimetal) (as phospholene oxides) Comparative Presence Absence Presence — —Unmeasurable Unmeasurable Unmeasurable Unmeasurable Example 1Comparative Presence Absence Presence — — Unmeasurable UnmeasurableUnmeasurable Unmeasurable Example 2 Comparative Absence Absence Presence0 — Unmeasurable Unmeasurable Unmeasurable Unmeasurable Example 3Reference Presence Absence Absence 0 10 2377 Absence 100 ppm or less 100ppm or more Example 3 (as alkali metal) (as phospholene oxides)Comparative Absence Absence Absence 34.2 — — — — — Example 4 (*1): “ppm”means “ppm by mass”. (*2): “Not detected” means any value less than adetection limit value of 1 ppm by mass.

Each carbodiimide compound could be obtained in Examples 1 to 16, andthe phase transfer catalyst (C) or the end-capping agent (D-1) was usedto result in a decrease in time taken for carbodiimidization in Examples6 to 16.

Neither a dimer, nor a trimer was detected in the resulting carbodiimidecompound.

On the other hand, other isocyanate compound was compounded instead ofthe aliphatic tertiary isocyanate compound (A) to cause gelation inComparative Examples 1 to 2.

Other isocyanate compound was compounded instead of the aliphatictertiary isocyanate compound (A) and thus no carbodiimide compound couldbe obtained in Comparative Example 3.

Magnesium ethoxide was compounded instead of the organic alkali metalcompound (B) and thus no carbodiimide compound could be obtained inComparative Example 4.

The catalyst could be removed by a simple operation, as in Example 16.

Examples 17 to 26

Each carbodiimide compound shown in Table 3 was added to a mixedsolution of a polyester-based polyurethane resin (Elastollan XNY585N-10(manufactured by BASF SE)) dissolved in DMF/THF so that the compoundingratio (solid content (active component) equivalent) shown in Table 3 wasachieved, thereby obtaining each polyester-based polyurethane resincomposition (solution).

A PET film release-treated by a Control Coater IMC-7013 model was coatedwith the solution and dried at 80° C. for 5 hours to obtain a 100-μmresin sheet. The resin sheet was formed into a strip sheet having awidth of 10 mm and a length of 70 mm.

The tensile strength of the strip sheet was measured by a tensile tester(“3365” manufactured by Instron).

The strip sheet was mounted in a highly accelerated life test apparatus(“PH-2KT-E”, thermo-hygrostat manufactured by Espec Corp.; temperature80° C., relative humidity 95%) and subjected to a moist heat treatmentfor 15 days. The tensile strength of the strip sheet after the moistheat treatment was measured by the tensile tester.

The respective average values of the tensile strengths of five stripsheets before and after the moist heat treatment were calculated, andthe strength retention ratio of the average value of the tensilestrengths after the treatment to the average value of the tensilestrengths before the treatment was calculated.

The results are shown in Table 3.

Comparative Example 5

A strip sheet was produced in the same manner as in Example 17 exceptthat no carbodiimide compound was added to a mixed solution of apolyester-based polyurethane resin (Elastollan XNY585N-10 (manufacturedby BASF SE)) dissolved in DMF/THF, and was subjected to the same testsas in Example 17.

The results are shown in Table 3.

TABLE 3 Characteristic Polyester-based evaluation polyurethane resincomposition Strength retention Polyester- ratio (hydrolysis basedCarbodiimide resistance) polyurethane compound 80° C., 95% RH resinparts by 20 days parts by mass Type mass % Example 17 99 Example 1 1 81Example 18 98 Example 1 2 90 Example 19 99 Example 2 1 14 Example 20 98Example 2 2 60 Example 21 99 Example 8 1 80 Example 22 98 Example 8 2 89Example 23 99 Example 13 1 65 Example 24 98 Example 13 2 78 Example 2599 Example 16 1 68 Example 26 98 Example 16 2 81 Comparative 100 — — 9Example 5

As clear from Table 3, the resin sheet obtained with the polyester-basedpolyurethane resin composition to which the carbodiimide compound wascompounded was excellent in hydrolysis resistance.

1. A method for producing a carbodiimide compound, comprising acarbodiimide production step of reacting an aliphatic tertiaryisocyanate compound (A) in the presence of an organic alkali metalcompound (B) having Lewis basicity.
 2. The method for producing acarbodiimide compound according to claim 1, wherein the organic alkalimetal compound (B) having Lewis basicity is at least one of a metalalkoxide, a metal amide, and a metal carboxylate.
 3. The method forproducing a carbodiimide compound according to claim 1, wherein thealiphatic tertiary isocyanate compound (A) is a compound in which atleast one aromatic ring is bonded to a tertiary carbon atom to which anisocyanate group is bonded.
 4. The method for producing a carbodiimidecompound according to claim 1, wherein the aliphatic tertiary isocyanatecompound (A) is at least one of tetramethylxylylene diisocyanate and3-isopropenyl-α,α-dimethylbenzyl isocyanate.
 5. The method for producinga carbodiimide compound according to claim 1, wherein the aliphatictertiary isocyanate compound (A) is reacted in the presence of theorganic alkali metal compound (B) having Lewis basicity and a phasetransfer catalyst (C) in the carbodiimide production step.
 6. The methodfor producing a carbodiimide compound according to claim 5, wherein thephase transfer catalyst (C) is at least one of crown ether, a quaternaryammonium salt, and a compound represented by the following generalformula (1):

wherein X and Y are each independently a methyl group, an ethyl group, apropyl group, a butyl group, or a phenyl group; R¹ is an alkylene grouphaving 2 to 3 carbon atoms; and m is an integer of 2 to
 500. 7. Themethod for producing a carbodiimide compound according to claim 1,wherein the method comprises an end-capping step of end-capping aportion of an isocyanate group in the aliphatic tertiary isocyanatecompound (A) with an end-capping agent at at least one time point amongthree time points, before the carbodiimide production step, during theproduction step, and after the production step, and the end-cappingagent is a compound (D-1) represented by the following general formula(2-1):

wherein Z is a methyl group, an ethyl group, a propyl group, a butylgroup, or a phenyl group; R² is an alkylene group having 2 to 3 carbonatoms; and n is an integer of 2 to
 500. 8. The method for producing acarbodiimide compound according to claim 1, wherein the method comprisesa chain extension step of reacting a portion of an isocyanate group inthe aliphatic tertiary isocyanate compound (A) with a chain extender atat least one time point among three time points, before the carbodiimideproduction step, during the production step, and after the productionstep, and the chain extender is a compound (D-2) represented by thefollowing general formula (2-2):

wherein R³ is an alkylene group having 2 to 3 carbon atoms; and p is aninteger of 2 to
 500. 9. The method for producing a carbodiimide compoundaccording to claim 1, wherein the method comprises an adsorption andremoval step of performing adsorption and removal of the organic alkalimetal compound (B) having Lewis basicity, with an adsorbent (E), afterthe carbodiimide production step.
 10. The method for producing acarbodiimide compound according to claim 9, wherein the adsorbent (E) isat least one of a synthetic aluminum silicate-based adsorbent, syntheticmagnesium silicate, an acidic cation-exchange resin, a basicanion-exchange resin, alumina, a silica gel-based adsorbent, azeolite-based adsorbent, hydrotalcites, a magnesium oxide-aluminumoxide-based solid solution, aluminum hydroxide, magnesium oxide, and analuminum hydroxide-sodium hydrogen carbonate coprecipitate (dawsonite).11. A method for producing a stabilizer having a purity of 90% by massor more and comprising no phospholene oxides or comprising phospholeneoxides at a content of 1 ppm by mass or less, wherein the methodcomprises the production method according to claim 1.